NATURAL SCIENCES OF PHILADELPHIA. 193 



Habitat. Near Merida, Yucatan. Coll. Couiision Cientifica under Arthur 

 Schott. 



Allied to the c i n e r e u s and sputator, and somewhat intermediate be- 

 tween them. The second from Mexico. 



Pharyngodon petasatus. 



Char. Gen. Fam. Hylidse. No fronto-parietal fontanelle ; prefrontals exten- 

 sively in contact anteriorly, developed into an angulated preorbital crest. 

 Corium entirely involved in the ossification of the cranial bones, to which 

 the epidermis is closely adherent. Tympanum distinct; vomerine teeth pre- 

 sent, a longitudinal series on the paraaphenoid bone, tongue round, but little 

 free. Digits normal, the posterior webbed. 



This genus is strictly a member of the Hylidae, as lately defined,* and 

 allied to Trachycephalus ; the character in which it differs from that genus, 

 and which is unique in the whole order of Salientia, is the presence of a 

 longitudinal series of teeth on the parasphenoid bone. If this point is unique, 

 the physiognomy of the animal is equally so, its profile resembling that of Aeto- 

 batis, or some allied genus, more than anything else in the animal kingdom. 

 This results from the extraordinary development of the canthus rostralis, 

 which forms a transverse wing entirely across the muzzle, and prominent 

 angular process in front of and continuous with the superciliary border ; and 

 the more excessive prolongation of the angular outline of the maxillary and 

 premaxillary bones. The latter projects in a more convex arc than the out- 

 line of the former, and as far beyond the mouth as the external nostrils are 

 in advance of a line connecting the orbits. The mouth is, therefore, very in- 

 ferior, its margin being a little behind the opening of the aforesaid nares. 

 The outlines of the muzzle are recurved and serrate, leaving the loreal region 

 as a gutter, overhung by the canthus rostralis. Straight sutural grooves out- 

 line all the bones of the cranium, as in Trachycephalus scutigerus, 

 leaving the ethmoid plate nearly an obliquely placed square. The border of 

 the cranial casque is a straight line just behind the tympanum, elevated, con- 

 tinuous, and serrulate. A strong ridge passes over the tympanum and joins 

 on bordering the orbit. Supercilia much elevated, eyes large, directed 

 nearly forward, protected behind by a large development of the united 

 palpebral, the opening about three times the size of the tympanum. Between 

 supercilia proper equal from occipital crest to union of canthus rostralis ; 

 from latter to premaxillary border, one half the same. Breadth between 

 maxillary ridges at canthus oris less than length of casque, and three and a 

 half times into total length. Vomerine teeth in two rounded ridges nearer 

 each other than to the nares, and behind posterior border of latter. Para- 

 sphenoid series simple, as long as from nostrils to premaxillary border. 



Abdominal areolae wanting on breast and gula, but extending on pre- 

 brachial and lateral regions, otherwise nearly smooth. Tibia half the length 

 to orbit ; foot rather short, digits stout, web measuring three-fifths of the 

 longest. Fingers free, stout ; dilations not broad. 



Above ashen olive, with many irregular brown spots ; external surfaces of 

 limbs barred with the same. Head blackish, with white punctulations. 

 Below uniform ashy white. 



Length of cranium, 12.1 lines ; of body from casque, 24.2 lines ; from ax- 

 illa to wrist, 10.1 lines; of hand, 8 lines; femur, 12 lines ; tibia, 14 lines; 

 foot, 19.3 lines. 



Habitat. The vicinity of Merida, Yucatan. A 9 specimen, No. 363 of 

 the collection made by authority of Jose Salazar Starregui, Governor of 

 Yucatan, by Arthur Schott, Naturalist of the Comision Cientifica de Yucatan. 



According to the notes of Arthur Schott, this animal was taken from a hole 

 in the rocky wall of the Cenote Pamanche, on the new road to Progreso. 



* Nat. Ilist. Review, London, 1865, p. 108. 



1865.] 



