10. TRIPEIOTf. 



431 



10. TRIPRION. 



Pharyngodon, Cope, Proc. Ac. Philad. 1865, p. 193. 

 Triprion, Cope, Proc. Ac. Philad. 1866, p. 127, and Journ. Ac. Philad. 

 (2) y\. 1866, p. 85. 



Pupil erect. Tongue subeircular, scarcely free behind, entire. 

 Yomerine teeth, and a series of parasphenoidal teeth. Head a bony 

 casque, with projecting labial borders. Tympanum distinct. Fingers 

 with a slight rudiment of web ; toes webbed, the tips dilated into 

 regular disks. Outer metatarsals united. Omosternum cartilagi- 

 nous ; sternum a cartilaginous plate. Diapophyses of sacral vertebra 

 strongly dilated. 



Yucatan. 



1. Triprion petasatus. 



Pharyngodon petasatus, Cope, Proc. Ac. Philad. 1865, p. 193. 

 Tripriou petasatus. Cope, Proc. Ac. Philad. 1866, p. 127, and Journ. 

 Ac. Philad. (2) vi. 1866, pi. 25. f . 7 & 8. 



Upper Tiew of heaJ. Lateral view of head. 



Open mouth. 



Vomerine teeth in two small groups between the choanse ; para- 

 sphenoidal teeth in a simple series. Head entirely bony, rough ; snout 

 quite flat, projecting far beyond the mouth-opening, the latter being 

 very infeiior ; canthus rostralis and superciliary ridges forming an 

 elevated ridge ; hinder edge of casque straight, raised ; tympanum 

 half the diameter of orbit. Fingers with a slight rudiment of web ; 

 toes short, two-thirds V»i^bbed ; disks smaller than the tympanum ; 

 subarticular tubercles moderate. The hind limb being carried for- 

 wards along the body, the tibio-tarsal articulation reaches between 

 the shoulder and the eye. Skin smooth above, granulate beneath. 

 Brownish above, spotted with darker ; head with white punctua- 

 tions : whitish beneath, immaculate. Male with an external sub- 

 gular vocal sac ; during the breeding-season the inner side of the 

 first finger covered with blackish rugosities. 



Yucatan. 



a-b. 

 c-d. 



6. 



Yucatan. 

 Yucatan. 



M. G. A. Bouieuger [P.]. 



