105 



neural arch is, in two cases, broad aiul 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 vertebrae 

 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 vertebrae resemble Sphargis moi'e 

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

 be referred to the dorsnl 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 modium contniin 0. 0:17 



Width of the iiiediiim coutrum 0. 0110 



Length between tlie margins of the zygapopb.vses of the mcdinm centrum 0. 0(>0 



Width between the anterior margins of fhe zygapophyses of the medium centrum 0. 070 



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



Width between the anterior bases of tlie arch 0.070 



Width of the arch at the middle 0.028 



Lengtii of the arch at tlie middle (*• O-JO 



Width of the posterior zygapophyses of No. 2 0.048 



Width of the arch O.O'i'J 



' See Teuiniinck and .Schlegel Tauna Japoiiie.a, Reptiles, Tab. 1-4. 



14 



