THE BATRACHIA OF NORTH AMERICA. 391 



The members of this family show no great difference in the structure 

 of the sternal apparatus. The precoracoids are always present, their 

 axis being parallel with that of the coracoids, and their distal extrem- 

 ity resting upon that of the latter. The precoracoids are much weaker 

 than the coracoids. In most genera an omosternum and a sternum are 

 well developed, aud furnished with a bony style. In Oxyglossus, Hy- 

 lixalus, and Prostherapis the sternum lacks the bony style, and so does 

 also the omosternum in Nannophrys and Phyllodromus. 



The vertebrae are proccelous. The urostyle is attached to two con- 

 dyles. There are no ribs. 



A frontoparietal foutanelle is constantly absent. 



The distal phalanges may be simple, pointed, or subtriangular, T- 

 shaped, Y shaped, or even claw-shaped (Hylambates), the latter struct- 

 ure being met with elsewhere in the Hylidae, Amphignathodontidse, and 

 Hemiphractidse only. 



Members of the Rauidse existed during the Miocene period. The re- 

 mains of Bana meriani* indicate a species as large as E. esculenta. Rana 

 noeggerathi, also from the Braunkohle near Bonn, was a small species? 

 of which I have not been able to learn the form of the sternum. If 

 the species was not a Rana, it did not belong to any other existing ge- 

 nus of the family. The genus Asphserium t (found in the Oeningen 

 bed) possessed a humerus without terminal condyle. This may be the 

 result of accident to the skeleton. 



The skeletal modifications in this family are those of the ethmoid aud 

 prefrontal bones and of the posterior extremity. 



The genera of the Eanidse are as follows : 



1. External metatarsals bound together ; omosternum and sternum both without 



osseous style. 

 Pupil vertical ; tongue emarginate ; vomerine teeth ; toes free 



Nannohatrachus Blgr. 



Pupil horizontal ; tongue emarginate ; vomerine teeth ; toes free 



Nannophrys Gthr. 



II. External metatarsi bound ; omosternum with style ; sternum without style. 



Pupil horizontal; tongue heart-shaped; no vomerine teeth; toes webbed, 



tips with disk Hylixalus Esp. 



Pupil horizontal; tongue entire; no vomerine teeth; toes free; tips with 



disks Prosthera]}is Cope. 



Like Prostherapis, but the tongue emarginate (Blgr.) Phyllobatest Bibr. 



III. External metatarsi bound together; omosternum without, sternum with, os- 

 seous style. 

 Pupil horizontal; tongue entire; no vomerine teeth; toes free ; tips with 



disks Phyllodromus Esp. 



* Von Meyer, Palseontographica, in, p. 127. 



] A. reussii Von Meyer, I. c, ii., p. 68. 



t This genus, which I placed provisionally in the Cystignathidae, not having seen 

 the sternum, belongs here according to Bouleuger. The name must be, therefore, 

 erased from the table on page 313. 



