186 PROCEEDINGS OF THE ACADEMY OF 



from Agassiz, who mingles these types with those of Amydse, and to regard 

 the Testudinata as primarily divisible into three orders or suborders, Chelo- 

 nii, Amydse and Pleurodira.* 



The name Chelopus Rafinesque has been recalled by Leconte, as identical 

 with Calcmys, Ag., to which Nanemys, Ag., must probably be united, and 

 which have been previously named Geoclemmys, by Gray. The present spe- 

 cies is in any case congeneric with G. annulata, Gray, which is of terres- 

 trial habit. 



Pectoral plates normal, broad, sternum notched behind. Feet very short, 

 clubbed, quite as in the Testudhfidse, digits flattened above* last phalanges 

 only distinct, not webbed ; claws short, obtuse. Head very small, covered 

 with a smooth skin, without sub-divisions. Eyes lateral, with a transverse 

 depression between them ; muzzle short, nearly vertical, swollen above, nos- 

 trils anterior. Alveolar plate narrow, without median ridge, cutting edge 

 smooth, neither notched, hooked nor toothed at the symphysis. Mandible 

 broad. A strong zygomatic arch. 



In a 9 specimen the dorsal region is elevated with a trace of a broad keel, 

 as in Cistudo, and the sides are steep. The outline is parallelogrammic, 

 rounded at the extremities. Posterior slope regularly oblique. Margin no- 

 where reflexed, posteriorly weakly serrate. Twenty-five subquadrate margi- 

 nals, the nuchal broad behind. Vertebrals, the four anterior of equal breadth, 

 the anterior pentagonal, the remainder hexagonal. All the plates concentri- 

 cally sulcate, with a slightly rugose areola. Inguinals very small ; sterno- 

 costal bridge very broad. Lobes of sternum short, free outlines, subquinque- 

 lateral. Large scales all round the forearm and foot, (seven rows anteriorly, 

 two rows of three each behind,) on the sole and heel only of the hind foot. 

 Above dark brown ; sternum black, bordered with yellow ; remaining under 

 surfaces yellow ; forelegs with a black stripe on ou'er edge. Top of head 

 black ; a narrow red band from behind and above the eye to the middle of the 

 neck, above and below which are black lines on a yellowish ground ; neck 

 below immaculate. 



This species is more elongate than C. annulatus; anal and gular plates 

 larger; color of head and extremities different. It is nearer the C. areola- 

 tus,f A. Dum., but is even more testudiniform. The latter is less elevated, 

 the hind feet a little webbed ; the carapace more elongate and narrowed ante- 

 riorly ; the artist has given six vertebral shields ; the anterior lobe of the plas- 

 tron is considerably shorter. 



One 9 specimen in the Smithsonian Museum, obtained in Yucatan by 

 Arthur Schott, naturalist to the Scientific Exploration of that country. 



In a female from Tabasco the frontal depression is less marked and the 

 muzzle not quite so rounded. In a male from the same locality the muzzle 

 is elongate and the vertex and front fiat. This is evidently the E. scabra fi- 

 gured by Bell, agreeing with it in the superior position of the head bands, etc., 

 thus differing from the allied dorsalis Gray, Spix. The carapace differs from 

 that of the Yucatan female in sexual characters, as the revolution of the 

 margins, but has a very small nuchal shield, and the first vertebral prolonged 

 between the marginals, while the former exhibits a short broad shield. This 

 is the only difference which cannot be regarded as sexual. 



This, with the following seven species of Tortoises below enumerated, was 

 presented to the Smithsonian Institution by Dr. Berendt, who, during a resi- 

 dence at Tabasco, Mexico, devoted much attention to the natural products and 

 features of the country. He has furnished me with the following notes on the 

 Testudinata. The specimens are complete and of adult age. 



The Chelopus punctularius is the Mojina of the natives of Tabasco. 



" Mojina is often found tame in the houses, and attaches itself very much 

 to men. The very same specimen which I brought living with me, and left 



* Vid. Proc. Acad. Phil., 18C4, 181. 



t Suspectod by Agassiz to be thn Malacoelemuiys palustrisof North America. 



[Oct. 



