452 BOULENGER. 



Measurements in Millimeters. 



R. draytonii R. aurora. 



Snout to vent 100 100 



Head 34 36 



Width of head 36 35 



Eye 12 11 



Tympanum 8 7 



Fore Umb 75 66 



Hind Umb 173 170 



Femur 50 48 



Tibia 51 52 



Foot 56 53 



There is not much light to be derived from these measurements ^^ 

 considering the individual variation shown by the specimens tabulated 

 by me under R. draytonii, all of which, I am convinced, belong to one 

 species only. 



12. Rana pretiosa. 



Rana pretiosa Baird and Gir., Proc. Ac. Philad., 1853, p. 378; Baird, 

 Proc. Ac. Philad., 1854, p. 62; Girard, U. S. Explor. Exped., Herp., p. 20, 

 PI. II, figs. 13-18 (1858); Cooper, Rep. U. S. Explor. Surv., XII, part 2, p. 304 

 (1860); Cope, in Hayden's Rep. U. S. Geol. Surv. Montana, p. 469 (1872); 

 BouLENG., BuU. Soc. Zool. France, 1880, p. 208, and Cat. Batr. Ecaud., p. 43 

 (1882); Cope, Proc. Ac. Philad., 1883, pp. 16, 20; Test, BuU. U. S. Fish Comm. 

 XI, 1892, p. 58; Stejneg., N. Am. Faun. No. 7, part 2, p. 225 (1893); Dick- 

 ERSON, Frog Book, p. 218, Pis. xvi, lxxxiii (1906); Camp, Univ. Calif. Publ. 

 Zool., XVII, 1917, p. 123; Bouleng., Ann. and Mag. N. H. (9) III, 1919, p. 410. 



Rana temporaria pretiosa Cope, Batr. N. Am., p. 432, figs. (1889); Meek, 

 Field Col. Mus., Zool. I, 1899, p. 232. 



Rana pretiosa luteiventris H. B. Thompson, Proc. Biol. Soc. Washingt., 

 XXVI, 1913, p. 53; Camp, t. c, p. 123. 



Vomerine teeth in oblique groups close together just behind the 

 level of the choanse. 



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

 rounded, feebly projecting beyond the mouth, as long as or a little 

 longer than the eye; canthus rostralis obtuse; loreal region oblique, 

 feebly concave; nostril equidistant from the eye and from the tip 



13 Which, contrary to Miss Dickerson's definition, shows a sUghtly shorter 

 hind limb in R. aurora as compared with R. draytonii. 



