AMERICAN FROGS OF THE GENUS RANA. 455 



Although this frog bears a general resemblance to R. teviporaria, 

 it is difficult to understand how a herpetologist of Cope's standing 

 should have regarded it as only subspecifically distinct from that 

 species. It is true the subordination of R. aurora to R. agilis is an 

 even more inconceivable example of laxity in his treatment of the 

 subject. R. pretiosa differs from R. tcmporaria in the more oblique 

 loreal region, the usually narrower interorbital space, the frec^uent 

 presence of a very distinct outer metatarsal tubercle, and, above all, 

 in the absence of vocal sacs in the male. It is further to be observed 

 that the A-shaped glandular ridge, accompanied by a dark marking, 

 which is frequent in R. tcmporaria and in the European and Asiatic 

 species that cluster round it, is constantly absent in R. pretiosa as 

 well as in the other American species. 



For measurements of Rana pretiosa see p. 454. 



13. Rana cantabrigensis. 



Rana cantabrigensis Baird, Proc. Ac. Philad., 1854, p. 62; Bouleng., 

 Bull. Soc. Zool. France, 1880, p. 209, and Cat. Batr. Ecaud., p. 45 (1882); 

 Cope, Proc. Amer. Philos. Soc, XXIIl, 1886, p. 519, and Batr. N. Am., p. 435 

 (1889); Bouleng., Ann. and Mag. N. H. (6) VIII, 1891, p. 453; Howe, Proc. 

 Bost. Soc. XXVIII, 1899, p. 369; Dickerson, Frog Book, p. 211 (1906); 

 Bouleng., Ann. and Mag. N. H. (9) III, 1919, p. 410. 



Rana tcmporaria, var. silvatica, part., GuNTH.,Cat. Batr. Sal., p. 17 (1858). 



Rana sylvatica Bouleng., Bull. Soc. Zool. France, 1879, p. 174. 



Rana cantabrigensis latiremis Cope, t. c, p. 520, and op. c, p. 435; Howe, 

 t. c. p. 373. 



Rana cantabrigensis evittata Cope, op. c, p. 435. 



Vomerine teeth in small oblique groups just behind the level of 

 the choanse, close together or at least nearer to each other than to the 

 latter. 



Head a little broader than long, rather strongly depressed; snout 

 rounded or obtusely pointed, more or less projecting beyond the 

 mouth, as long as or a little longer than the eye; canthus rostralis 

 obtuse; loreal region oblique, concave; nostril equidistant from the 

 eye and from the tip of the snout, or nearer the former; distance 

 between the nostrils greater than the interorbital width, which is f 

 to f that of the upper eyelid ; tympanum more or less distinct, about ^ 

 the diameter of the eye and 2 to 3 times its distance from the latter. 



Fingers moderate, obtuse, first longer than the second, third a little 

 longer than the snout; subarticular tubercles moderate. 



