28 PROCEEDINGS OP THE ACADEMY OP 



rowed, and there are two anal scuta whose average length equals 

 that of the femorals. The median suture of the abdominals is 

 only one-third that of the pectorals (three-fifths in G. angustatus). 

 Tail very short, with four series of minute tubercles above. Length 

 of carapace .1 18 m., width .079. 



Color above dark brown ; plastron light reddish-brown (Bo- 

 court), neck yellowish below. 



From Mexico. 



CLAUDIUS ANGUSTATUS, Cope. 



Proceed. Acad. Nat. Sci. Phila., 1865, p. 187; Proceed. Anir. Phil. Soc, 



1869, tab. ix. 



This species is rather more slender than the last; the head is 

 narrower, and the posterior lobe of the plastron narrower and 

 more acute. The horny plate on the nose, and the undivided 

 dorsal keel, constitute other distinctions, the last of which are 

 noticed by Bocourt. In one of our specimens there is a single 

 anal scutum, in another there are two. 



STAUREMYS, Gray. 



Proc. Zool. Soc. London, 1864, p. 127 ; Supplement to Catal. Shield Rep., 



1870, p. 65, f. 22. 



This name was applied b}^ Dr. Gray as a subdivision of Stauro- 

 typus, Wagl., which belongs to the Kinosternidse, a family defined 

 by the absence of the mesosternal bone. If this arrangement 

 expresses the true affinities of the species referred to it, it is un- 

 necessary to introduce it here. Dr. Gray states that the anterior 

 lobe of the sternum is movable as in Staurotypus tr-iporcatus, but 

 is more acute than in that species, being in this respect like the 

 posterior lobe. This difference is only specific, and the supposed 

 genus Stauremys, as defined by Gray, would not appear to stand 

 on any foundation. Should, however, it turn out to embrace a 

 species of Chelydrinee, it will rest on the character given above, 

 as distinguishing it from Claudius, viz., the movable anterior lobe 

 of the sternum. M. Bocourt appears to believe it to be one of 

 this group, from his referring to it a species of Claudius (G. 

 pietus, Cope), and as he may be correct, I introduce it into the 

 present synopsis. 



Dr. Gray's descriptions render it plain that the only known 

 species is quite distinct from those described above. 



[June 25, 



