[189] 



Art. IV. — On the Families of the Rciniform Anura. 

 By E. D. Cope. 



It has been already pointed out* that the families of the toothless Anura, or 

 Bufoniformia, are distinguishable into those with the arciferous and those with the 

 ■ raniform types of sternum. To the first were assigned the families Rhinophrynidas 

 and BufonidjE, and to the last, the Engystomidos, BrachymeridEe, and Dendrobatidaa. 

 Continued observation points to the radical nature of this diversity, while the increase 

 of knowledge furnishes us with cases of rudimental dentition, indicating a less signifi- 

 cance for the character which lias been supposed to characterize the Bufoniformia. 

 Such occurs in ihe genus Colostethus Cope, which seems to be quite identical with 

 Dendrobates, except in the possession of teeth. Microhyla, a true Engystomatid, is 

 said by Gilnther to possess teeth, and minute rugosities on tlie maxiila3 of Callula 

 natatrix deceived me into the belief at one time that teeth actually existed. Among 

 arciferous genera Eupemphix Steindachner is said by him to possess very minute 

 teetli, which in some adults are entirely wanting. I therefore inclitie to believe 

 that the families of the Bufoniformia must be separated, and referred to the neighbor- 

 hood of those types of Arcifera or Raniformia to which they are most nearly affined. 



In reviewing the structures of the genera with raniform sternum, it appeared that 

 the family of Bracliymeridte did not represent a natural group, embracing genera 

 related by analogy rather than affinity. The opportunity of studying Phrynomantis 

 [Bradnjmerus) afforded by the Museum Couipar. Zoology, shows that it is a degraded 

 form of those Engystomatoid genera without epicoracoid, and should be referred to 

 the family Engystomidte. The genera, mostly American, furnished with epicoracoid, 

 represent the family Pliryniscidas. Chelydobatrachus should be referred to the 

 Bufonida3, and Breviceps is the type of a peculiar family. 



The family Rhinophrynida; will remain with the Bufonid;x? in the Arciferous 

 series, but its chai'acters must be modified by the removal from it of the genus 

 Ilemisus Gthr. This is as might have been anticipated, and is the result of a differ- 

 ent interpretation of the pieces of the scapular arch. In this genus the arch is very 



* Nat. Hist. Review, London, 18G5. On the Batrachia Salientia. 



48 



