FROGS OF SOUTHEASTERN BRAZIL — COCHRAN 129 



5. rubra — group 



This group of short-legged hvHds takes its name from its earliest 

 known species, Hyla rubra Daiidin, described from the Amazon region, 

 and includes crospedospila, cuspidata, fuscomarginata, juscovnria, 

 hayii, parkeri, perpusilla, similis, squalirostris, strigilata brieni, strigilata 

 Jlavoguttata, and strigilata strigilata. In none of these species does the 

 adpressed heel reach beyond the nostril; coarse brovvn reticulations 

 enclosing yellow or reddish spots arc usuallj'- found on the concealed 

 surfaces of the legs and groin; and in nearly every one the tibia is 

 noticeably enlarged, almost equaling the heavy femur in diameter. 

 H. catharinae Boulenger (1888c, p. 417), from Santa Catarina, is closely 

 related to H. strigilata brieni. I include photographs of the t3rpe of 

 catharinae in plate 13 for comparison. 



The group characters are not difficult to recognize, but the specific 

 characters are extremely hard to distinguish, due to their considerable 

 instability. For instance, hayii and nasica will probably never be 

 completely separated in southern Brazil, since individuals with char- 

 acters midway between the accepted norms of the two are occasionally 

 found in populations having predominantly the characters of the one 

 or the other. While mathematical analysis is of help in some large 

 series, much work on the variation of broods of known parentage, 

 similar to that on Eleutherodactylus by Goin (1950), needs to be done 

 before accurate final results can be achieved. 



For a statistical analysis of members of the rubra group here 

 discussed, see pages 373 and 378. 



Key to the frogs of Group 5 from southeastern Brazil 



a'. Fingers free. 



b^. Vomerine teeth between the choanae. 



c'. Nostrils twice as far from eye as from tip of snout; interorbital diameter 

 equals width of upper eyelid; tympanum separated from eye by }^ its 

 diameter; disks of third finger and fourth toe covering Yi tympanum; 



size moderate, up to 45 mm fuscovaria (p. 137) 



c'. Nostrils four times as far from eye as from tip of snout; interorbital 

 diameter VA times width of upper eyelid; tympanum separated from 

 eye by a distance equaling its own diameter; disk of third finger covering 

 tympanum, of fifth toe covering }i tympanum; size small, up to 27 mm. 



perpusilla (p. 145) 

 IP. Vomerine teeth on level with posterior borders of choanae. 



c'. Nostrils three times as far from eye as from tip of snout; interorbital 

 diameter slightly less than width of upper eyelid; disk of third finger 

 covering % tympanum, of fourth toe more than Yz tympanum; size 



moderate, up to 40 mm strigilata brieni (p. 154) 



c'. Nostrils twice as far from eye as from tip of snout; interorbital diameter 

 twice width of upper eyelid; disks of third finger and fourth toe covering 

 34 tympanum; size moderate, up to 40 mm. . . squalirostris (p. 151) 

 262006—55 10 



