50 PROCEEDINGS OF THE ACADEMY OP 



Fitz., thi3 name must become a synonyme of Phrynoi'dis, and the genu3 to which 

 I fiist applied it be called Incilius. The species which truly belong to it 

 are I. lentiginosus, cognatus, woodhousei, americanus, n e- 

 bulifer, veraguensis, coniferus, d i a lo p h u s, and probably bi- 

 porcatus. The species d'orbignyi, c e 1 eb e nsi s and occellata 

 formerly referred to it, must be placed in Phrynoi'dis Fttz. 



Bufo diptychus Cope, 1. c, 353, is the species described by Dr. Girard, a3 

 B. poeppigii Tsch., in Herpetology of U. S. Exploring Expedition. It is 

 distinct from Tschudi's toad. 



CERATOPHRYDID.E. 



This family has been recognised in an indefinite way by Dr. Tsehudi,* who 

 gives as its distinguishing features " kopf sehr gross, eckig, schief nach vorn 

 verliingprt ; Hautverlangerungen am obern Augenliede." He includes in it the 

 genera Ceratophrys, Phrynocerus, Megalophrys and Asterophrys. The unnatu- 

 ral nature of this union has been demonstrated by Dr. Giinther, who places 

 Asterophrys and Megalophrys in separate families, and assigns Ceratophrys with 

 Phrynocerus to the Ranidae. The Ranidae of Giinther is, however, a hetero- 

 geneous group ; and I would separate under Tschudi's name those genera of 

 toad-like animals in which the manubrium sterni is wanting. These are Cera- 

 tophrys, Phrynocerus and Pyxicephalus ;f probably Calyptocephalus will enter 

 the same series ; but these I have not seen. Tschudi's inapplicable characters 

 may be replaced by the following. Form slout, bufonine ; .head broad, elevated, 

 Os maxillare toothed. Extremities short ; digits without terminal discs ; the posterior 

 more or less webbed. Ear perfectly developed. Diapophysis of sacral vertebra cylin- 

 drical. Manubrium sterni ivanting. Faratoids present or absent. I am not now 

 acquainted with other peculiarities, though they doubtless exist. 



The S y stem of Opisthogloss Anura proposed by Giinther, like the system of 

 Ophidia of the Erpetologie Generale, is a valuable index of the subject, but not 

 an exposition of the scheme of nature. I have already J ventured the opinion 

 that a primary division into forms with, and forms without dilatations upon the 

 extremities of the digits cannot be maintained : this character must be sub- 

 ordinated, as that of the presence or absence of teeth on the maxillary bones 

 as employed by Dumeril and Bibron, has been by Giinther himself. He at- 

 taches greater value to the former because it "is connected with a strongly- 

 marked distinction in the mode of life." This appeal to adaptations is not 

 uncommon ; but we now know enough of the system, to believe that the 

 relations of its parts are to be determined by homological and embryological 

 considerations combined, which coincide also with chronological and geogra- 

 phical. Have we not creatures of similar habits and adaptations in the most 

 diverse groups? It is enough to mention to a herpetologist the arboreal 

 Viperidce and Crotalidas ; the corresponding types of Pleodonta and Ccelodonta, 

 of Acrodonta and Pleurodonta; the gill-bearing Siredonand Siren, and a host 

 of other such ; the parallelisms of the Implacental and Placental Mammalia, 

 etc. Also the supposed Neotropical Shrikes and Certhiidse are Clamatores, and 

 the supposed Salmonidse are Characins. In comparing many of these cases, 

 we observe, too, how by approximation in time, analogy becomes affinity. 



In pursuance of this view, the probability of a distinction between the Hylodidae 

 and Cystignathidae of Giinther has appeared to the author to vanish in great mea- 

 sure. The discovery of the genus Tarsopterus of Reinhardt and Liitken, in con- 

 nection with that of Plectromantis, by Wagner, has confirmed this opinion. The 

 two genera are incontestably nearly allied, as urged by Reinhardt.|| though the 



* Classif. der Batrachier, 26. 



t Stannius' statement, "Zootomie der Amphibien," p. 17, that Pyxicephalus possesses the manu- 

 brium, relates properly to the species now called Tomopterna, which were formerly included under 

 that genus. 



J Proc. Acad. Philada.. 1862. p. 351. 



|| Videnskab. Meddelelser Kjobenhavn, 1862, p. 240. 



[Mar. 



