Dr. J. E. Gray on Ghelonians. 305 



Hydraspis maculata. Hand-list Sh. Rept. p. Qb. 



Head large, Jbrown above and below, with a broad streak 

 from nostrils, under the eye, continued along side of head, 

 including ear and on the upper and lower lips ; back of neck 

 smooth ; the hinder part of the throat white. Dorsal shield 

 brown, with a white spot in the middle of the upper edge 

 of the first costal. The underside of the margin, triangular 

 marks on the upper edge of the margin, the sterno-costal 

 sutures, the lateral sides of the front lobe, and the hinder 

 part of the hinder lobe of the sternum pale. A rhombic 

 spot occupying the greater part of the disk of the sternum 

 dark brown ; this spot is acutely angular in front, and rounded 

 behind. 



Hah. Tropical America. 



ACANTHOCHELYS. 



Head oblong ; chin two-bearded ; back of neck covered with 

 conical spines. Thorax oblong, with a central longitudinal 

 depression. Nuchal plate distinct. Anterior vertebral plate 

 large (in the adult), about as long as broad, broad in front and 

 narrow behind ; the second and third elongate, six-sided. 

 Intergular plate broad, longer than the gular. 



Acanthochelys Spixiiy Hand-list Sh. Rept. p. 66. 

 Hydraspis Spixii. 

 Hob. Brazil. 



In the British Museum we have a specimen of this species 

 which is covered with short, rigid confervoid fibres. It was 

 for many years in spirits, but has lately been stuffed. 



Mesoclemmys, Hand-list Sh. Rept. p. 66. 



Head moderate, depressed; eyes anterior; crown broad, 

 extending to the occiput ; the sides rather concave, covered 

 with regular-shaped shields — two pairs in front and two behind, 

 and one elongated hexagonal central. Temples covered with 

 polygonal shields. Tympanum large, superficial. Back of 

 neck granular. Chin two-bearded. 



Shell solid, rather depressed. Nuchal shield distinct. 

 Anterior vertebral shield elongate, wider behind ; the fourth 

 and fifth keeled. 



This genus is between Hydraspis and Platemys in the form 

 of the skull, but is known from both by the regular shields on 

 the head. 



Ann. c& Mag. N. Hist. Ser. 4. Vol. xi. 20 



