CHELYS. 43 



Hydraspis constricta, Emys constricta, Cuv. MSS. (v. t. 

 Mus. Par.) Scutello nuchali angustato. 



Hydraspis MaximiUam, Emys MaximUian't. Mikan. 

 Chelodina Maximiliani, Fitz. Hab, in Brazilia. 



Hydraspis pachyura. Boie, MSS. (v, Mus. Leyden.) 



Hydraspis larbatula, Emys larbatula, Gravenhorst, 

 Delic. Mus. Zool. t. 5, f. 3, 4. 



The figures of this species are from foetal specimens ; they 

 have no nuchal plate, and two beards on the chin ; both of 

 which characters are common to many of the other species. 



Hab. in BrasiUa. 



Gen. 4. CHELYS, [Matamata.) 



Caput latissimum depressum, labiismollibus; nares elongati 

 tubulares. Sternum continuum, scutellum intergulare mar- 

 ginale, nuchale distinctum. 



The head flat, broad, fringed with warty appendices; 

 the eyes small ; the nose elongated into a thin tubular pro- 

 boscis ; the mouth round ; the jaws covered with a soft skin, 

 the lower one elevated behind ; the os hyoides very compli- 

 cated. (See Cuv. Os. Fos. v. t. f. ; and skeleton Mus. Col 

 Surg.) The neck thick, flat, long, with a double series of 

 membranaceous appendices on the sides. The shell oval, 

 convex, broader before ; acutely three-keeled ; the middle 

 of the back flattened; shields thin, angularly gibbous; sternum 

 narrow, rather broader and rounded in front, narrower and 

 acute behind ; the intergular plate marginal ; the legs scaly ; 

 the tail rather long and warty. Only one species has been 

 well described ; but M. Geoff"roy has indicated another from 

 a very young specimen ; and Daudin, from some notes of 

 Ruiz de Zelva, has described, under the name of Testiido 

 hispinosa, what Dr. Schweiger considers a third species. If 

 his character, however, is correct, which is very doubttul, 

 it must belong to the Emydse. 



1. Chelys Matamata, [Brazilian Matamata.) Testa oblonga 

 tricarinata, scutellis elevatis acutis, capite corporeque rufes- 

 centibus, gula nigro lineata. 



