In the figures of the Argentine specimen the last ten caudals are practically without characters, and it is perhaps allowable to question whether the terminal two or three were not added to make an even taper to the end of the column. If such be not the case, this specimen had more vertebræ than any other.
Newport(male).—The seventh cervical vertebra presents a conical metapophysis, which on the first thoracic vertebra forms of a rather thick, long, declining process ending in a facet for the tubercle of the first rib. This metapophysis maintains nearly the same form as far as the sixth thoracic vertebra, but on the third thoracic a mammiliform process makes its appearance on the anterior margin near the tip, and becomes more prominent on each succeeding vertebra. On the seventh thoracic it becomes larger, thin, and upright, and widely separated from the articular facet for the tubercle of the rib. On the centrum of this vertebra lower down is a second much larger rugose articular facet. On the eighth thoracic vertebra the upper articular process disappears altogether and is replaced by a transverse process on a lower level, with a facet at the free end for the rib. On the ninth thoracic the transverse processes are larger and nearly straight. They are longer on the first lumbar and incline a little forward. Those of the succeeding vertebræ are similar, but decrease gradually in length, while somewhat increasing in breadth. They are last traceable on the ninth caudal. On the eighth caudal they are perforated by a foramen.
All the vertebræ from the first cervical backward have neural spines as far as and including the eleventh caudal. The spine on the first thoracic is rather short, narrow and pointed. These spines increase in height in succeeding vertebræ as far as the sixth lumbar; at the same time the breadth increases antero-posteriorly and the tip becomes expanded. The spines are nearly equally high on all the succeeding lumbars, but begin to decrease on the caudals and disappear altogether on the eleventh caudal.
The anterior zygapophyses and metapophyses maintain a nearly constant position close to the top of the centra throughout the column, from the seventh thoracic backward, and are vertical, thin, and oblong, squared or rounded. They begin to decrease in size noticeably on the first caudal, and on the seventh caudal are mere swellings at the sides of the nearly horizontal plate from which the neural spine springs. They are traceable as far as the twelfth caudal.
A ridge appears on the side of the neural arch near its base on the fifth caudal and is stronger and very marked on those following, to the ninth caudal. A ridge unites the anterior and posterior facets for the chevrons on the ninth and succeeding caudals.
Barnegat City(female).—Unlike the Newport skeleton, there are no neural spines on the fifth, sixth, and seventh cervicals. The spine on the first thoracic vertebra is quite short and sharp, and on the second, third, and fourth thoracics also is rather pointed, though of increased length. There is no metapophysis on the seventh cervical.
On the seventh thoracic the facet for the tubercle of the rib, instead of being very prominent, becomes inconspicuous. The metapophysis is flat and squared, and there is no lower facet on the side of the centrum. On the eighth thoracic the metapophysis is thin, squared, and vertical, and a well-formed transverse process appears on the side of the centrum. The transverse processes of the ninth thoracic are a little curved backward, and on the first lumbar and succeeding vertebræ bent forward. These processes are less tapering on all the lumbars than in the Newport skeleton. They disappear on the eighth caudal. None is perforated.
The longest neural spine is on the sixth lumbar, and on all the lumbars both the anterior and posterior edges are somewhat convex. Hence their shape is rather different from those of the Newport skeleton, in which the anterior margins are somewhat concave. The tips of the spines are rather suddenly expanded. The spines of the caudals are rather more expanded at the tip and more inclined backward than in the Newport skeleton. They disappear on the eleventh caudal.
The horizontal plate joining the metapophyses is noticeable on the fifth caudal. The ridge on the side of the neural arch is first noticeable on the fourth caudal and is very strong on the fifth, sixth, and seventh. The metapophyses are last traceable on the twelfth caudal.
Charleston(female, jr.).—This skeleton resembles the Newport one as regards the facets for the articulation of the tubercles of the ribs, except that the seventh thoracic resembles the sixth and has no lower facet on the side of the centrum. The transverse processes of the ninth thoracic are rather strongly curved backward, while those on the last thoracic and first lumbar are nearly straight. On succeeding vertebræ they are inclined forward. They are last traceable on the eighth or ninth caudal (vertebra 35 or 36). None is perforated by a foramen.
Though the vertebræ are defective, there appear to have been no neural spines on the fourth to the seventh cervicals, inclusive. The spine on the first thoracic is short, and on the first to the fourth is pointed. The spine disappears on the tenth caudal (vertebra 37).
The metapophyses assume the vertical position on the eighth thoracic. The last of these processes is barely traceable on the tenth caudal (vertebra 37). The ridge on the side of the neural arch is well marked on the fifth to the ninth caudals, inclusive. On the seventh caudal (vertebra 34) the anterior and posterior facets for the chevrons are united on the right side, and on the eighth caudal and succeeding vertebræ on both sides.
Barnegat City(female).—The first four cervicals are united. The foramen above the anterior articular facets of the atlas is complete, and the edges of these facets are raised. The inferior lateral process is flat, broad, and strongly bent backward.
Second cervical: Inferior lateral process nearly as long as that of the first cervical; broad, flat, and bent backward parallel with the process of the first cervical. Superior lateral process short, strong, and flat. A large incomplete foramen between it and the inferior process.
Third cervical: A short, conical inferior process, curved forward.
Fourth cervical: Similar, but with smaller and shorter inferior process. Neural arch and spine complete; the latter fused with the preceding spines. Arch not reducing the size of the neural canal.
Fifth cervical: Arch and spine broken. Arch nearly as broad as the anterior epiphysis of the centrum. Inferior lateral process short, straight, and directed obliquely outward.
Sixth cervical: Spine broken. Arch complete, nearly as wide as the anterior epiphysis. Inferior lateral process short, thick, knobbed, and directed obliquely outward and a very little forward. The left longer.
Seventh cervical: Spine obsolete. Arch complete, as wide as the anterior epiphysis. No superior lateral process or metapophysis. A thick articular facet for the head of the first rib on the middle of the side of the centrum. No inferior lateral process.
Fused spines of the first to fourth cervicals bent backward; the mass broad antero-posteriorly and rounded at the tip.
Newport(male).—First cervical with the foramen over the anterior articular facets incomplete, and the borders of the facets less raised. The facets also broader and more declined. Inferior lateral process thicker, somewhat tapering, and nearly transverse.
Second cervical: Inferior lateral process much shorter than that of first cervical, about parallel with it, but with the tip bent forward. Superior lateral process short, thick, and bent backward; joined to the inferior process on the right side, inclosing an oval foramen.
Third cervical: A short, straight, triangular superior process on the right side; that on the left short and blunt. Inferior lateral process long, thick, club-shaped, and curved backward.
Fourth cervical: Inferior lateral process similar to the last in shape, but shorter, broad and flat, and only slightly curved backward. Neural arch and spine separate from those of the third cervical; the arch rather smaller than those preceding it, and reducing the size of the neural canal.
Fused spines of the first to third cervicals nearly vertical, rather high, and obtusely pointed.
Fifth cervical: Spine pointed and quite long. Arch complete. Inferior lateral process short, squared, flattened, and directed outward obliquely.
Sixth cervical: Spine about as long as on the fifth cervical. Arch much narrower than the anterior epiphysis. Inferior lateral process prominent, thick, somewhat compressed, and directed downward.
Seventh cervical: Spine as high as the arch, obtusely pointed. Arch complete, as wide as the anterior epiphysis. A strong conical superior lateral process, or metapophysis, on a broad base, directed forward. An articular raised facet on the side of the centrum, directed obliquely backward. No inferior lateral process.
Charleston(female, jr.).—The first to fourth cervicals resemble those of the Newport skeleton, but the fourth entirely separate. All the lateral processes undeveloped, or broken off, except the right inferior lateral process of the atlas,which is like that of the Newport specimen. The anterior foramen of the atlas is incomplete, as in that specimen, and the spines of the conjoined vertebræ are vertical and pointed. (Pl. 25, fig. 1.)
Fifth cervical: Spine wanting. Arch complete. Inferior lateral process undeveloped, or abraded.
Sixth cervical: Spine and processes broken. Arch wide.
Seventh cervical: Similar to that of the Newport skeleton, but the spine obsolete or broken.
Barnegat City(female).—First thoracic: Spine vertical, pointed, about as high as arch and centrum together. A moderately long process with articular facet for tubercle of rib on side of neural arch; facet elliptical and directed a little downward and forward. A smaller facet for head of second rib on posterior upper edge of centrum.
Seventh thoracic: Metapophyses long, extending horizontally, straight superiorly. A small articular facet on the outer side near the base, directed downward; strongest on right side. A very small facet on posterior upper edge of centrum, scarcely noticeable on right side. Neural spine rather narrow at tip; superior margin straight.
Eighth thoracic: Metapophyses squared and thin. A distinct transverse process on side of centrum about half as broad as the centrum is long, and as long as centrum is broad; flattened, squared, and a little curved backward and upward. Articular facet for rib elliptical and directed obliquely backward. A broad, shallow groove across base of transverse process, the anterior edge of which is emarginate proximally. Neural spine as in seventh thoracic.
Ninth thoracic: Metapophyses squared. Transverse process similar to that of eighth thoracic, but equal to centrum in length, little narrowed at base, and directed outward; anterior edge convex, posterior concave; articular facet occupying the posterior half of the distal edge. A very shallow groove proximally.
Newport(male).—First thoracic: Neural spine a little curved backward and rounded at tip; much higher than length of arch and centrum together. Articular facets as in Barnegat skeleton.
Seventh thoracic: Metapophyses similar in shape to those of Barnegat skeleton but with a very distinct facet on side of arch, terminating a process about as long as the greatest diameter of the facet; surface of facet rugose. Below this process, on side of centrum, a very large, oval, sessile facet, reaching forward nearly to the anterior face of the centrum and upward to its superior edge. A very low, small swelling on the posterior superior edge of centrum, probably indicating the point of attachment of a cartilage connecting the head of the eighth rib. Neural spine expanded at free end, and superior margin rounded.
Eighth thoracic: Metapophyses similar to those of Barnegat skeleton. A distinct transverse process nearly as broad as the length of the centrum, oblong or squared, flat, directed somewhat backward, but not upward. Articular facet for rib not occupying whole of free end and only slightly directed backward; anterior margin as in Barnegat skeleton. Neural spine similar to that of seventh thoracic.
Ninth thoracic: Similar to that of Barnegat skeleton, but transverse process longer than centrum and directed a little downward, articular facet occupying less than posterior half of free margin; proximal groove inconspicuous; anterior and posterior margins nearly straight.
Charleston(female, jr.).—The centra of the thoracic, as well as the lumbar, vertebræ in this individual present inferior median keels, and more or less concave sides, which is not the case in the Barnegat and Newport skeletons. This can not be due to immaturity, as in a still younger individual, supposed to representZiphius grebnitzkii, the thoracic vertebræ are rounded below. The neural spines of the thoracic vertebræ are much less inclined backward insemijunctusthan in the Newport and Barnegat skeletons, but this is doubtless connected with age, as the younger series of vertebræ already mentioned exhibits the peculiarity in a more marked degree. A similar modification dependent upon age appears to affectHyperöodon, as will be seen by comparing Van Beneden and Gervais’ figures in the Osteography, plate 18.
First thoracic: Similar to that of Newport skeleton, but spine not higher than arch alone. (A little abraded at tip, but probably undeveloped.)
Seventh thoracic: Metapophyses short (abraded), incompletely developed. A distinct facet on side of same on an elongated process, as in Newport skeleton, but no second larger one on side of centrum. No facet on superior margin of centrum either anteriorly or posteriorly.
Eighth thoracic: Transverse process similar to that of Barnegat skeleton, but anterior edge nearly straight; process about one-half as broad as length of centrum. (Indications of immaturity.)
Barnegat City(female).—First lumbar: Similar to last thoracic, but transverse process expanded distally and slightly directed forward; a little longer than centrum; anterior and posterior edges emarginate proximally.
Eleventh lumbar (last): Centrum very long. Neural arch and spine very high, more than twice length of centrum. Spine inclined backward much beyond posterior face of centrum; anterior margin straight, posterior convex, tip expanded. Transverse process a little more than one-half length of centrum, somewhat expanded at distal end and curved forward so that tip is about in line with anterior face of centrum. Metapophyses close to centrum and to each other, semihexagonal in outline. A sharp median inferior ridge, and shallow posterior oblique channels on under side of centrum.
Newport(male).—First lumbar: Similar to that of Barnegat skeleton, but transverse processes considerably longer than the centrum and not expanded at tip; anterior edge straight, posterior only slightly emarginate proximally.
Tenth lumbar (last): Centrum like that in Barnegat skeleton. Neural arch and spine only slightly higher than length of centrum. Transverse process oblong, free margin nearly transverse; process inclined forward so that tip is a little beyond anterior face of centrum. Metapophyses close to centrum, rounded in outline. Neural spine much inclined backward; anterior edge concave, posterior convex,tip expanded. A rounded inferior median ridge and very distinct oblique posterior channels on under side of centrum.
Charleston(female, jr.).—First lumbar: Similar to that of Barnegat skeleton, but transverse process directed outward and scarcely or not at all forward; length of process equal to that of centrum; tip rounded (due to immaturity).
Tenth lumbar (last): Centrum very long. Neural arch and spine a little less in height than length of centrum. Transverse process oblong, curved forward, more than one-half as long as centrum. Metapophyses similar to those of Newport skeleton. Inferior median ridge very sharp; lateral channels rather indistinct.
Barnegat City(female).—First caudal (vert. 28): Similar to last lumbar, but neural spine broader antero-posteriorly. Transverse process ࡪ length of centrum, inversely triangular, the tip much in advance of anterior face of centrum, free end somewhat rounded. Metapophyses similar to those of last lumbar. No median inferior ridge, but two short processes bearing facets for chevrons posteriorly and a very slight indication of similar process anteriorly, but without facets. Posterior inferior oblique channels indistinct.
Seventh caudal (vert. 34): Centrum (exclusive of chevron processes) nearly as deep as long. Neural arch and spine only a little higher than length of centrum, very much inclined backward and expanded at distal end; free border of spine straight. Metapophyses close to centrum, united nearly to tips by a horizontal plate. A ridge extends backward from their tips nearly across the arch. Another very prominent ridge traverses the centrum at the base of the arch. At the posterior end, a deep groove, convex forward, extends down the side of the centrum, making an emargination in the transverse process and proceeding thence down the lower side of centrum to its lower middle point, where it ends in a deep semicircular emargination between the anterior and posterior chevron facets. Transverse process a triangular stub, reaching nearly to the line of the anterior face of centrum. Chevron processes very large, and the median inferior surface of the centrum between them deeply grooved longitudinally.
Tenth caudal (vert. 37): Centrum as deep as long. Neural spine a low ridge, as long as the centrum, and extending beyond it posteriorly. No transverse processes. A foramen in side of centrum much above the middle and a similar one below. Close to the latter and below it another foramen pierces the ridge uniting the chevron processes, and appears below on side of longitudinal inferior median channel. Metapophyses small mammilliform processes on top of centrum.
Eleventh caudal (vert. 38): No processes. A very small neural spine. Posterior epiphysis strongly convex.
Twelfth caudal (vert. 39): A rounded mass without processes.
Thirteenth caudal (vert. 40): An oblong mass, with two grooves on each side, two widely separate foramina above and two closely approximated below, entering a common depression, with rounded projections on its borders.
Fourteenth caudal (vert. 41): Similar to thirteenth caudal, but with a single lateral groove.
Fifteenth caudal (vert. 42): Similar to fourteenth caudal, but sides extending upward and downward in a ridge. Inferior foramina nearly as far apart as superior and posterior epiphysis much smaller than anterior.
Sixteenth caudal (vert. 43): Similar to fifteenth caudal, but the disproportion of epiphyses greater and lateral ridges higher. Superior and inferior surfaces of centrum inclined.
Seventeenth caudal (vert. 44): Similar to preceding, but smaller.
Eighteenth caudal (vert. 45): Longer than high. Inferior ridge longer and larger than superior. Groove very large. Anterior face of centrum deeply concave, posterior flat. Posterior epiphysis very much smaller than anterior. Foramina very small, practically obliterated on right side.
Newport(male).—First caudal (vert. 27): Similar to last lumbar, but transverse process shorter, about two-thirds as long as centrum, oblong and but little constricted at base; distal margin nearly straight. The process does not extend forward quite to the line of the anterior face of centrum. No inferior median ridge, but strong posterior chevron processes. Postero-inferior oblique grooves very distinct.
Seventh caudal (vert. 33): Similar to the same vertebra in Barnegat skeleton, but neural spine more inclined backward and anterior border deeply concave. Metapophyses oblong, directed upward, not reaching anterior face of centrum as they do in Barnegat skeleton. Anterior face of centrum receding superiorly and the ridge opposite it on side of centrum shorter than in Barnegat skeleton. Ridge behind metapophyses indistinct. Postero-inferior oblique grooves as in Barnegat skeleton, but piercing transverse process, forming a foramen. Anterior and posterior chevron processes very large and receding very much, as do also the anterior and posterior faces of centrums.
Eleventh caudal (vert. 37): Similar to Barnegat skeleton, but spine shorter than centrum and not extending beyond it anteriorly or posteriorly. Metapophyses similar, but wider apart.
Twelfth caudal (vert. 38): Neural arch barely complete. No spine.
Thirteenth to nineteenth caudals (vert. 39-45): Similar to those of Barnegat skeleton.
Twentieth caudal (vert. 46): Rudely triangular, with a peg-like posterior projection, bearing the very small posterior epiphysis. No foramina. Anterior epiphysis deeply concave in middle.
Charleston(female, jr.).—First caudal (vert. 28): Similar to last lumbar, but only a faint inferior median ridge. Inferior outline of centrum antero-posteriorly very concave, which is not the case in the Barnegat and Newport skeletons. Posterior chevron processes prominent. Postero-inferior oblique grooves shallow.
Seventh caudal (vert. 34): Like the Newport skeleton. The transverse process not pierced or emarginate. Postero-inferior oblique grooves indistinct. Ridges on centrum very distinct. Right anterior and posterior chevron processes united and pierced by a foramen.
Tenth caudal (vert. 37): Similar to the same vertebra in Newport skeleton, but neural spine very short.
The number of chevrons in the North American and some other specimens is as follows:
The chevrons are similar in form in the three North American specimens, with some differences which will be pointed out below.
Newport(male).—The first chevron consists of a pair of bones which are not united. They are longer than deep, their depth indeed being less than that of any one of the succeeding bones except the tenth and eleventh. Each presents one strong superior articulating facet. Second chevron, elongated antero-posteriorly, but not much deeper than the first. Third chevron very deep and only equaled in that respect by the fourth; narrowed and rounded off below. Fourth chevron largest and broadest (antero-posteriorly) of the series; expanded below and the lower border transverse. Fifth to eighth similar in form, but less deep successively, and the lower border more rounded. Ninth similar to eighth, but smaller and thinner. Tenth similar to first, longer (antero-posteriorly) than deep. Eleventh similar to tenth in form, but smaller.
Barnegat City(female).—First chevron bone lacking. Second like that of Newport skeleton, but smaller. Third similar to second, but much larger and more produced posteriorly; quite unlike the third in the Newport skeleton in form, and much less deep. Fourth, largest and deepest of the series; anterior and posterior borders rounded, and the inferior border similar. Fifth to eighth similar in form, but successively less deep, and all more expanded below; inferior border nearly straight. Ninth similar to eighth, but depth not exceeding breadth; lower angles produced.
Charleston(female, jr.).—The chevrons of this specimen resemble those of the Newport skeleton, but on account of immaturity they are all more or less rounded. The two sides of the first chevron are united. The second is without the posterior angular projection seen in the other specimens. The third is the deepest of the series. The eighth is not deeper than long, and hence resembles the tenth chevron of the Newport skeleton in proportion, but is, of course, much smaller. Two or three chevrons are lacking from the posterior end of the series.
Barnegat City(female).—First rib shortest and broadest, but considerably broader at proximal end than at distal end. Head and tubercle close together. The succeeding ribs increase in length and decrease in breadth to the fifth or sixth. The third, fourth, and fifth are expanded and flattened at distal end. Seventh, eighth, and ninth successively shorter. Distance between head and tuberclegreater on second rib than on first, and on third is greater than on second. On the third to sixth, inclusive, the distance is about equal. The tubercle is scarcely distinguishable on the seventh rib, while on the eighth and ninth it is lacking, these ribs joining the transverse processes by a terminal facet only.
Newport(male).—Similar to those of the Barnegat skeleton, but first rib maintains nearly the same breadth throughout. Neck thicker than in Barnegat skeleton. Seventh rib terminates proximally in a single large rugose facet, which connects with a similar facet on side of centrum of seventh thoracic vertebra.
Charleston(female, jr.).—Similar to those of the Barnegat skeleton, but a distinct tubercle on the seventh rib. Eighth and ninth ribs end proximally in a transverse facet only, which is largest on the eighth. Tenth rib (represented by a fragment) only half as broad as the preceding ones and more nearly round in section.
Barnegat City(female).—Five segments. Manubrium wider than long, convex inferiorly. Deep anterior and posterior notches, about equal, the former with an angular projection on each side. Facet for cartilaginous sternal rib thick and prominent. Second segment wider than long, about equally notched anteriorly and posteriorly, the two sides anchylosed together by a bony bridge, about as wide as the notches are deep. Third and fourth segments similar to second but smaller; similarly notched; left portion a little longer than right. Fifth segment elongated, left side very much so; the two sides joined by a narrow bridge; posterior notch very deep.
Newport(male).—Similar to sternum of Barnegat skeleton, but manubrium scarcely wider than long; posterior notch much longer than anterior, with parallel sides. Second and third segments similar to those of Barnegat skeleton but sides of latter not completely anchylosed together. Fourth segment in two pieces, with a wide interval between. Fifth segment triangular with deep anterior, triangular notch, a narrow bridge, and short posterior prolongation (the left longer than the right).
Charleston(female, jr.).—Resembles the sternum of the Barnegat skeleton rather than that of Newport skeleton, but anterior parts cartilaginous. Opposite sides of second, third, and fifth segments anchylosed together and those of fourth segment nearly so. (Pl. 25, fig. 2).
Barnegat City(female).—Superior border irregular. Posterior angle acute. Anterior and posterior borders nearly straight. Ridges distinct. Acromion broad both at base and at tip, sharply bent upward, so as to be parallel with anterior border of scapula. Coracoid nearly as long as acromion, slender, a little curved upward, irregular and somewhat expanded at the end.
Newport(male).—Superior border irregularly rounded. Posterior angle obtuse, anterior angle projecting. Ridges indistinct. Anterior and posterior borders nearly straight, but irregular. Acromion broad at base, tapering toward thetip, which is again somewhat expanded; bent upward, but not sufficiently to be parallel with anterior margin of blade. Coracoid rather thick, irregular, strongly expanded at tip.
Charleston(female, jr.).—Rather too much abraded for comparisons, but posterior margin more concave than in either of the other skeletons.
Barnegat City(female).—Fore limb much shorter than in the Newport skeleton. Humerus: Head quite oblique, the lower edge overhanging the shaft considerably on the ulnar side. Tuberosity level with upper surface of head, elliptical in outline when viewed from above. Deltoid ridge moderately prominent, irregular, rugose, and extending to about the middle of the shaft. Distal end of humerus not expanded. Bicipital groove inconspicuous.
Radius: Almost perfectly straight, but a little inclined toward ulna at oblique proximal end; scarcely expanded at distal end, which is lower externally than internally.
Ulna: Much slenderer than radius, rounded triangular in section, not expanded at distal end, where the margin is lowest externally. Olecranon well developed, thin, and pointed proximally.
Carpals: Five; two on ulna side, two median and one on radial side in line with first metacarpal. The proximal middle bone (intermedium) extends much farther proximally than those on each side of it.
Metacarpals: Metacarpal III longest, metacarpal II broadest. Metacarpal I oblong, or rather conical, with a lateral enlargement, and situated in line with the distal row of carpals.
Digits: First phalange of first digit short and conical.
Newport(male).—Fore limb considerably longer and more massive than that of the Barnegat skeleton but similar otherwise, except as follows:
Humerus: Head rather larger and less inclined. Deltoid ridge more prominent.
Radius: Broader proximally and rounded at distal end, where it extends outward beyond the carpal bones.
Ulna: Thicker, and olecranon less pointed.
Carpal bones: Middle carpal bone not extending farther proximally than those on either side of it.
Metacarpals: Metacarpal I nearly square, third longest, second to fourth more constricted.
Digits: First phalange of first digit long and cylindrical. Phalangeal formula: I, 1; II, 6; III, 6; IV, 4; V, 2.
Measurements of the skeletons above described are as follows:
Dimensions of four skeletons of Ziphius cavirostris.