Zoological Society. 451 



PROCEEDINGS OF LEARNED SOCIETIES. 



ZOOLOGICAL SOCIETY. 



March 8, 1864.— D. J. E. Gray, F.R S., in the Chair. 



Descriition of a New Species of Staurotypus (S. Salvinii) 

 FROM Guatemala. By Dr. J. E. Gray, F.R.S., etc. 



Amojig the interesting series of Tortoises brought by Mr. Salvin 

 from Ilaumanchal, Guatemala, and deposited in the British Museum, 

 are two specimens of a Tortoise of the genus Staurotijpus, but dif- 

 fering from the normal form of that genus in the sternum being 

 narrowed and acute in front, like the sternum of Chelydra, which 

 genus it resembles in having a crested though short tail. 



I would propose to divide the genus thus: — 



A. Sternum broad and truncated in front. Staurotypus. 



1. Staurotypus triporcatus. Gray, Cat. Shield Rept. B. M. 

 47, t. 20 b. 



Hah. Mexico (JViegmann) ; Vera Cruz (SalU). 



B. Sternum narrow, tapering, acute in front. Stauremys. 



This subgenus has the form of the sternum and the crested tail of 

 Chelydra, with the sternal shields of Staurotypus. 



2. Staurotypus (Stauremys) Salvinii. 



JIab. Ilaumanchal, Guatemala (Salvin). 



Head very large, swollen, crown covered with a thin soft skin ; 

 face conical, rather produced ; nose terminal ; mouth inferior ; beak 

 large, dentated on the edge ; chin with two beards ; throat warty ; 

 skin of body and limbs granular ; the fore legs have several slender, 

 very broad, arched, band-like shields across the inner side, the 

 middle one being the broadest ; toes well developed, strong ; upper 

 surtace covered with a single series of band-like shields, united 

 to the claws by a wide, well-developed web; claws 4 — 5, strong, 

 elongate, acute ; tail short, conical, angular above, with a central 

 and lateral series of tubercles, fonning three short crests ; the tho- 

 rax oblong, covered with three short, continuous keels ; marginal 

 shields rather narrow, elongate ; sternum cross-like, small compared 

 with the dorsal disk, narrow, slightly rounded before, acute behind, 

 united to the dorsal disk by a narrow lateral process ; sternal plates 

 seven, thin, four pairs and a single odd one behind ; the first pair 

 elongate, longer than broad (probably the first two pairs of other 

 Emydee united) ; the second pair broad, produced on the side, so as 

 to cover the greater part of the cross-like sternum ; the third pair 

 elongate, narrow ; the hinder plate rhombic, rather longer than 

 broad, acute in front and behind; the axillary and inguinal plate 

 large, covering the space between the outer lateral edge of the second 

 pair of shields and the marginal plates. The front lobe of the 

 sternum is very moveable at the suture between the first and second 



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