CINOSTERNUM. 17 
8. Cinosternum leucostomum. (Tabb. XVI., XVII.) 
Cinosternon leucostomum, A. Dum. Cat. Méth. Rept. 1851, p. 17; and Arch. Mus. Hist. Nat. 1855, 
p. 239, t.17; Strauch, Vertheil. Schildkr. p. 99 ; Dum. & Boc. Miss. Sc. Mex., Rept. p. 25; 
Bocourt, Journ. Zool. 1876, p. 394; Cope, Proc. Ac. N. Sc. Philad. 1865, p. 189; and 
Journ. Ac. N. Se. Philad. viii. 1876, p. 153. 
Kinosternum scorpoides, Gray, Cat. Shield Rept. p. 44 (part.). 
Swanka maculata, Gray, Suppl. Cat. Shield Rept. p. 68. 
Hab. UNorrn America, New Orleans (Duméril, Strauch)—Mexico, Tabasco (Cope), 
Cosamaloapam * (Sallé); Guaremata, Rio Usumacinta (Duméril), Vera Paz 
(Bocourt, Salvin), Huamuchal (Salvin); Costa Rica, Sipurio, Old Harbour 
(Cope); Panama, Turbo (Smiths. Inst.).—CoLomB1a, Bogota (Dumeéril). 
Vernacular name: “ Pochitoque camatotl” (Tabasco). 
Shell with a single keel, most prominent on the two last vertebral scutes, and gene- 
rally inconspicuous on the middle of the back, which is flat. Convexity of the shell 
variable. First vertebral scute as broad as long, sometimes bell-shaped, with the lateral 
margins concave. Sternum not emarginate behind, the two lobes being attached to the 
fixed portion by well-developed straight joints. Central part of the sternum rather shorter 
than either of the two lobes. Gular plate large, generally about as long as the median 
suture of the front lobe. Axillary and inguinal scutes barely touching each other or 
entirely separate. 
The tail is very long and thick in the male, and armed with a large curved claw ; it 
is much smaller, tubercular, and provided with a small claw in the female. Head 
greyish brown above, mottled with yellowish; jaws without spots, either uniform 
yellowish or horn-coloured or blackish; the throat is sparsely mottled with brownish. 
Besides some specimens the origin of which is either unknown or uncertain, I have 
before me a series of seven examples collected by M. Sallé in Mexico and by Mr. Salvin 
in Guatemala; they are the types of Gray’s Swanka maculata. The shell of the longest 
is 54 inches long. 
9. Cinosternum brevigulare, sp.n. (Tab. XVIII. fig. A.) 
Hab. Mexico, Playa Vicente (Sai/é). | 
This species is distinguished, first by having a scarcely movable hind lobe, which is 
attached to the sternum by a suture rather than by a joint, and secondly by the shortness 
of the gular plate, the length of which is only two fifths of the median suture of the 
front lobe. Shell with a distinct broad keel; first vertebral as long as broad; axillary 
and inguinal scutes separate. Head brown above, marbled with whitish on the sides; 
jaws whitish ; throat slightly mottled with brownish. 
* This is a town on the banks of the Papaloapan river. The latter name has become “ Papalco Apoia ” in 
Gray’s Suppl. Cat. Shield Rept. p. 68! 
BIOL. CENTR.-AMER., Rept., May 1889. *3 
