450 



BOULENGER. 



Dickerson, the upper parts are brown, yellowish, or olive; there may 

 be small spots or specks of dark brown or black on head, back, and 

 sides; much red on the parts of the legs and feet which are concealed 

 when folded, or the sides of the body, and at the base of the arms; 

 reticulations of yellow and black on the body and thighs where they 

 lie against each other. Throat and belly white, mottled with dark. 



Male without vocal sacs; fore limbs strong; a thick pad on the in- 

 ner side of the first finger. 



Nasal bones small, transverse, with concave posterior border, 

 separated from each other and from the ethmoid, which is obtusely 

 pointed in front. 



The tadpoles of R. draytoni and R. aurora have not been described. 



Habitat. — Washington, Oregon, and California. 



Measurements in Millimeters 



cf 9 9 



From snout to vent 54 76 73 



Head 18 26 25 



Width of head 19 26 25 



Snout 6 9 8 



Eye 6 8 8 



Interorbital width 2.5 3 3 



Tympanum 3.5 5 5 



Fore limb 35 48 47 



1st finger 7 9 10 



2nd " 7 9 9 



3rd " 11 13 14 



4th " 7 10 10 



HindHmb 101 136 128 



Tibia 31 42 39 



Foot 34 43 41 



3rd toe 16 22 21 



4th " 28 35 34 



5th " 18 26 26 



Specimens from Seattle, Washington. 



This frog is very closely related to R. draytonii, with which I had 

 previously united it (Ann. & Mag. N. H. [6] VIII, 1891, p. 453), but 

 it appears to be distinguishable, in addition to minor points, by the 

 smaller tympanum, as pointed out by Baird & Girard in the original 



