105 



neural arch is, in two cases, broad and flat; in two others, there is an obtuse 

 keel. 



The centra, apart from their arches, are puzzling bodies, especially since 

 in the present case, they are somewhat flattened by pressure. They differ 

 materially in size ; one of them being twice the size of the others. The 

 smaller ones are of the ball-and-socket type, and have a deep longitudinal 

 groove on each side. The thicker portion of the centrum forms the inferior 

 boundary of this pit-groove, while a thinner portion, possibly a diapophysis, 

 limits it above. It is, however, thin, and had no great length. There is no 

 sign of chevron bones and articulations, so that these vertebrae may have been 

 cervical. Their bodies are, however, shorter and wider than in those vertebra? 

 of any known tortoise. A groove on the upper surface represents the neural 

 canal ; while a flat area on each side, in front, supports the neurapophyses. 

 The large centrum exhibits the superior groove and antero-lateral platform 

 for support of the neural arch. One end is cupped obliquely, while the other 

 is nearly plane, with the same obliquity and a slightly-raised margin. Its 

 outline is subtriangular. The lower side of this centrum possesses a short 

 keel posteriorly. The sides exhibit no pit, but have a thin edge, which is 

 concave behind the middle, and then turned outward. I can see no articu- 

 lation for a rib. 



The forms and characters of these vertebras resemble Sphargis more 

 than anything yet described. 1 Either the large or the small, or both, must 

 be referred to the dorsal region ; in this case, the concavity of one extremity 

 is a new feature among tortoises, so far as known. The great freedom of the 

 arch from the centrum is very peculiar; while it; is probable that the articula- 

 tions of the ribs were to the middle of the side of the body, and not to the 

 adjacent parts of two bodies, and may have been (see below) to processes or 



diapophyses. 



Measurements. 



M. 



Length of the medium centrum 0. 037 



Width of the medium centrum 0. 060 



Length between the margins of the zygapopbyses of the medium centrum 0. 060 



Width between the anterior margins of the zygapopbyses of the medium centrum 0. 070 



Width between the posterior margins of the zygapopbyses of the medium centrum 0. 047 



Width between the anterior bases of the arch 0. 070 



Width of the arch at the middle 0.028 



Length of the arch at the middle 0. 040 



Width of the posterior zygapopbyses of No. 2 0.048 



Width of the arch , 0.025 



1 See Temmiuck and Schlegel Fauna Japouica, Reptiles, Tab. 1-4. 



14 c 



