60 THE EXTINCT BATEACHIA, REPTILIA 



tebrae and the head of the femur; the third a nearly perfect vertebra and diapophysis of another, with dermal bones; 

 the fourth the greater part of the femur, with fibula and dermal bones; fifth, ribs and dermal bones, with pelvis. 



Seven vertebra present centra, and are more or less nearly perfect. There are probably no cervicitis, but there are 

 three forms of diapophyses which indicate different positions in the vertebral column. 



That which I suppose to represent the most anterior, has a short, wide diapophysis with tubercular articular sur- 

 face, and a short knob with capitular articulation at the base of the anterior aspect of the neurapophysis, with its su- 

 perior margin on the plane of the diapophysis. In the next, the diapophysis is short, wide, and closely connected at 

 the base with a capitular articular tubercle, for the rib, the extremity of the diapophysis furnishing the tubercular 

 surface. In the first of these the diapophysis is as long as the elevation of the anterior zygapophysis above the cen- 

 trum, and the capitular knob measures the middle of the latter space with its superior margin, being in the plane of 

 the diapophysis. In three others the elevated position of the capitular articulation is visible. The second form of 

 diapophysis is seen in a nearly perfect vertebra in immediate connection with that first described above, but probably 

 in abnormal relation. The process is narrower, but flat, and without capitular process at base, nor is there any cap- 

 tular articulation on the centrum. Its position is much lower than in those just described, being opposite to the 

 middle of the centrum. Its extremities are imperfect, probably broken off. I suspect that their condition is indicated 

 by an isolated diapophysis, which is accompanied by tubercular articular face at a distance of 18 lines from its extrem- 

 ity, and probably at some distance from its base, which is, however, lost. The third type of diapophysis is seen in two 

 examples; one, in normal relation to its centrum, etc. This is quite slender and elongate, compressed at base, and 

 cylindric throughout most of the length. On the posterior face of the extremity is a slightly concave articular face; 

 the extremity proper appears also to have borne the tubercular face. That these are the combined tubercular and ar- 

 ticular facets is rendered altogether probable by their wider separation on the second example of this form. This is 

 an isolated diapophysis, of slender cylindric form, which, at a distance of an inch from the extremity dilates into a 

 right-angled flat process, whose distal side bears a narrow capitular articular face. The extremity is subcylindric, 

 bearing the tubercular facet. 



This arrangement of the vertebra? is confirmed by the arrangement seen in other species, where vertebras similar 

 to those first described are evidently dorsal. It is probable from the above, that the capitular articulation rises from 

 the centrum very soon in this type, as in the Crocodilia, perhaps very few dorsals retaining it on that portion; and 

 differing from the Dinosaurian type, where this facet is on the margins of the centra and not elevated on a pedicel. 

 This form differs from the Crocodiles in the narrowing and final cylindric form, as well as descent on the centrum of 

 those diapophyses on which the two facets approach and unite. 



One objection to the position assigned to the last form of vertebra, is the fact that the only one with perfect cen- 

 trum presents an oblique truncation on the posterior margin on each side, which looks much like a capitular articular 

 face. There is a precisely similar vertebra in the Museum of the Acad. Natl. Sciences, from Chatham Co., N. Ca., 

 which is ascribed to the B. caroliuensis. Their surface is concave in this specimen, but seems too large for the head 

 of a rib. In both, the vertical diameter is one-half the transverse width of the articular face of the centrum. I can- 

 not assign the place or use of this facet with certainty, but the following light is thrown upon the point by another 

 specimen in the Museum Academy, also from Chatham Co., N. Ca., presented by Prof. Emmons. 



It consists of five consecutive vertebrae on a block of coal slate, of which the anterior two present the capitular 

 tubercle elevated to the base of the short flat diapophysis, without being confluent with it in the first, but closely 

 united to, and of equal length with the shortened second. On the third, the rib-diapophysis becomes abruptly very 

 much wider, and occupies a position a little lower down on the centrum. The diapophysis is preserved on one side of 

 the block. It is flat, a little narrowed beyond the middle, then dilated, and with an open emargination opening pos- 

 teriorly and outwards, at the distal extremity. 'With the extremity it bears a narrow articular surface. These I sus- 

 pect to represent capitular and tubercular articulations. The fourth and fifth vertebra; bear each, a greatly dilated 

 and thickened diapophysis, which I have little doubt represent the sacral supports of the ilium. Their expanded 

 bases are somewhat lower in position than the diapophyses of the vertebra in advance, and they occupy a broad arti- 

 cular face of their proper vertebra, and a distinct facet of that preceding, leaving an articular face on its posterior 

 margin. I suppose the peculiar vertebra; already alluded to iu the B. lepturus and specimen from North Carolini, 

 are, therefore, the last lumbars. 



