NATURAL SCIENCES OF PHILADELPHIA. 51 



latter only has paratoid glands. Their margined toes are but a step beyond those 

 of certain Cystignathi ; their digital dilatations are as distinct as those of many 

 Hylodidaj. The family of Cystignathida?, thus composed, would contain the 

 types Platyplectrum Gthr., Limuodynastes Filz., Cystignathus Wagl, Pleuro- 

 dema Tsch., ?Gomphobates R. and L., Ischnocnema R. and., Liuperus D. and 

 B., Tarsopterus R. & L., Plectromantis Peters, Crossodactylus Bum., Bibr.,Fhjl- 

 lobates Bibron, Hylodes i'ftz., (or the genera into which the last may be divided.) 

 In this association the paratoids of Plectromantis have but little weight, as in 

 Pyxicephalus in our Ceratophrydidre ; and it is probable that it will again be 

 found that their presence or absence is immaterial in the definition of certain 

 families in the Anura, although others may be well characterized by them, a3 

 in Gunther's method. The genera Pelodryas Gthr., and Scytopis Cope, with 

 large paratoids will probably be referred to the Hylidae, which has been defined 

 as destitute of them. 



Pyxicephalus cultripes. 



Ochntophrynus cultripes Rhdt. and Liitk., Videnskab. Meddelelser, etc., 

 Kjobenhavn, 1862, p. 159. 

 If we introduce the presumed genus Odontophrynus into Dumeril and Bib- 

 ron's table of genera of Raniformia, the only character which seems to separate 

 it from Pyxicephalus is the concealed tympanum of the former, as distinguished 

 from its visibility in the latter. This character is sometimes of very little value, 

 the tympanic disc being more or less distinct in different individuals of the 

 same species of many Anura, in proportion to the tenuity of the epidermis. 

 This is especially seen in species of Bufo. The text relating to Pyxicephalus 

 americanus, however, settles all doubts, as it says, M Tympan imperceptible 

 au travers de la peau." In their Latin diagnosis, Reinhardt and Liitken say 

 " dentes** non in palato ;" but in the text, " To langagtige i midten ikke sam- 

 menstodende Tandgrupper ere stillede paa Ganen mellem de indre Naesebor," 

 etc. As the figure represents palatine teeth, they are doubtless present. The 

 species cannot, therefore, be separated from Pyxicephalus. It is very nearly 

 allied to, if not identical with, the frog called Pyxicephalus ? n. sp., in the 

 recently-published Catalogue of the collection brought home by the United 

 States Paraguay Expedition.* 



ALYTID.E. 



SCAPHIOPCS. 



The species of this genus are seven in number ; they are found throughout 

 the temperate regions of North America, and as far southward as the City of 

 Mexico. They represent the single Alytes obstetricans of Europe, which 

 differs in its want of manubrium sterni, its slightly-webbed toes, and its cunei- 

 form bone forming but a tubercle ; and the Helioporus albip u n c t at us of 

 Australia, where there is a spur upon the thumb, and trihedral diapophysis of 

 sacral vertebra. They may be at once separated by means of the following 

 synopsis : 



I. A gland in the upper integument of tibia. 



Head short; tympanum concealed mu Itiplicatus. 



II. No gland in upper integument of tibia. 

 at. No pectoral glands. 



/?. Length of tibia three times frontal breadth. 

 Muzzle depressed, prominent. 



Tympanum concealed conchii, 



Muzzle elevated, truncate in profile. 

 Front plane ; 

 Loreal region covex, oblique varius. 



1863.] 



* Proc. A. N. S., Phil., 1862, 352. 



