194 ON THE FAMILIES OF THE RANIFORM ANURA. 



This genus is represented by two species of the Pal^otropical. and two of the 



Neotropical region. One of the latter exhibits free toes, and metatarsal tubercles so 



reduced as to constitute an approximation to Engystoma. 

 a. Toes webbed. 



S. marmoratuin Cuvier. {Engystoma) Rana systoma Schneider, Hist. Amphib., 

 Peters, Moiiatsber. Berl. 1863. Uperodon D. B. Gacopus Gthr. Systoma les- 

 chenaultii Tschudi. The Carnatic, India. 



S. g 1 b u 1 o s u m, Gacopus glohulosus Giinther, Kept. Brit. India. Madrsi^. 



S. variolosum Cope, Proc. Ac. Nat. Sci. 18fi6. {Engystoma.) Costa Rica, Cen- 

 tral America. 



aa. Toes free. 

 S. us turn, Engystoma ustam Cope, Proc. A. N. S. Phila. 1866. Guadahixara and 

 Yera Cruz, Mexico. 



ENGYSTOMA Fitzinger, Dum. Bibron. 

 Stenocepliahis TsdmAu McVojjs Wagler. " Oxyrhynchus {Yalenc.) Guerin." Di- 

 plopehna Gthr., Peters, Steind. 



a. Toes webbed. 

 E. orn a t u m Dum. Bibr. Diplopelma Gthr. Catal. Madras, India. 

 E. pule brum Hallowell, Proc. Academy, 1862; Giinther, Kept. Brit. India. 



{Diplopelma). China. 

 E. d i s c i f e r u ni Peters, Monatsberichte, 1867 {Diplopelma). Java. 



««. Toes free. 

 E. Caroline use Holbrook, N. Am. Herp. Tab. Dum. Bibr. Southern United 



States. 

 E. ovale Schneider, Hist. Amph. Bufo Surinamensis Dand. Engystoma Fitz., 



Dum. Bibr., Gthr., Steindachner, Verb. K. K. Zool. Bot. Gessel. "Wien, 1864. 



Tab. Surinam, Brazil and Buenos Ayres. 

 E. mi crops Dum. Bibr. Steindachner, 1. c. Tab. Brazil. 



Species of this family have been artificially distributed among various genera and 

 families. Diplopelma, supposed to differ in its palmate feet, is connected by species 

 having rudimental webs, with the webbed species. Systoma appears to be distinct, 

 so far as known, though the vomerine teeth supposed to characterize it are found by 

 Giinther not to exist, while the metatarsal shovels assigned to it occur in the Mexican 

 S. variolosum Cope, slightly less developed, and in the S. u s t u m Cope, so 

 reduced as to approach Engystoma. 



