270 BULLETIN 34, UNITED STATES NATIONAL MUSEUM. 



Oregon and California. I think B. pictiis is the young of this form. To 

 the typical B. columUensisholong^o^. 328, 2577, 2579, 4975, 9950, 10920, 

 and 11510. To the intermediate type belong 9630, 8093, 11500, 11922, 

 and 11923. To the halophilus type may be referred Nos. 2581, 9405, 

 11535, 11921, and 11922. No. 11505 is intermediate in the form of the 

 parotoids, and the web is deeply excavated, bat the free portion of the 

 toes are widely margined. A complete series of the forms of the paro- 

 toid may be traced, beginning with the short type of halophilus, No. 

 2581, through 13608, 11505, 11535, to 11923 of the elongate form. 



In Nos. 4975 and 9950 there are distinct traces of superciliary cranial 

 ridges. They are perfectly straight, and there is no indication of post- 

 orbital ri Iges. There are four specimens under 4975, and they are from 

 Chilowyuck, Wash. Ter. The locality of the other specimen is unfortu- 

 nately unknown, The same character is seen in the type of B. micro- 

 scaplms, according to my description, which is given below. The sijeci- 

 meu is unfortunately inaccessible to me at present. 



" Upper surface of head nearly plane upon its middle region ; orbits 

 bordered by a low and rounded off ridge; its skin being thin and ad- 

 hering to the skull. Parotoids well developed and subreniform. Eyes 

 and tympanum -rather large. Tongue elongated, broadest posteriorly. 

 Upper jaw emarginated. Two large carpal callosities. A membra- 

 nous fold at the inner lower edge of the tarsus. Toes palmated; two 

 metatarsal tubercles. Palms and soles coarsely granular. Upper sur- 

 face of body exhibiting numerous glandular tubercles ; large pustular 

 swelling upon the thighs. Color uniformly dark green." 



I also add a copy of my description of the young, under the name of 

 B. pictus, as it embraces some peculiar characters, probably due to im- 

 maturity : 



" Palmar and solar tubercles well developed, the larger or inner one 

 of the latter not bearing a cutting edge. Cranium plane above; the 

 muzzle produced, rather narrowed, and vertically truncate. Memhramim 

 tympani very small, externally invisible ; ostia pharyngea exceedingly 

 minute. Tongue large, oval, extensively free. Parotoids superior, 

 broadly oval in form. Upper surfaces covered with large tubercles; 

 inferior surfaces areolate. Limbs stout, especially the tarsus, which 

 bears a longitudinal fold. The heel reaches to the middle of the par- 

 otoid gland, and the toes are only webbed at the base." The palmar 

 and solar tubercles are yellow, and the warts of the body tipped with 

 red; size small. 



There is a direct relation between the climatic conditions of the regions 

 and tbe forms of this species which inhabit them. It is well known that 

 the degree of humidity of the Pacific region increases rapidly as we pass 

 from south to north. The southern part of the region inhabited by 

 this toad is quite arid, and the opportunity for aquatic life must be 

 limited. Accordingly the natatory web of the hinder foot is reduced. 

 In the specimens from the rainy north the web is much larger and the 

 colors arc darker. This increase of pigment is confirmatory of J. A. 



