10. TRIPRION. 431 
10. TRIPRION. 
Pharyngodon, Cope, Proc. Ac, Philad. 1865, p. 193. 
Triprion, Cope, Proc. 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 acartilaginous plate. Diapophyses of sacral vertebra 
strongly dilated. 
Yucatan. 
1. Triprion petasatus. 
Pharyngodon petasatus, Cope, Proc. Ac. Philad. 1865, p. 193. 
Triprion petasatus, Cope, Proc. Ac. Phalad. Spe Pp. 127, and Journ, 
Ac, Philad, (2) vi. 1866, pl. 26, f. 7 & 8 
Upper view of head. Lateral view of head. Open mouth. 
Vomerine teeth in two small groups between the choane ; 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 ; eanthus 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 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. 
Gn. Yucatan. M. G, A. Boulenger [P.]. 
ce-d, 2. - Yucatan. 
