10. TKIPKION. 



431 



10. TRIPEION. 



Pharyngodon, Cope, Proc. Ac. Philad,. 1866, p. 193. 

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

 (2) vi. 1866, p. 85. 



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

 Vomerine 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 petasatns. 



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

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

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



Upper view of head. 



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 inferior ; canthus rostralis and superciliary ridges forming an 

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

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

 toes short, two-thirds webbed ; 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-6. 

 c-d. 



Yucatan. 

 Yucatan. 



M. G. A. Boulenger [P.]. 



