area marked with one or two dark spots, and back of this is another 

 light tubercle or swollen area. The head is short and broad with the 

 nostrils far apart. 



Structure: Hind legs shorter; head relatively narrower; tym- 

 panum smoother than in Rana boylii boyiii; web of hind foot very 

 large, extending to tips of toes; tips of toes not much expanded; dorso- 

 lateral fold strongly pitted anteriorly; swelling on thumb of male 

 bilobate. 



Voice: No data. 



Breeding: As soon as ice has melted in the mountain lakes, they 

 breed in June and July. The eggs are approximately like those of 

 Rana boylii boylii (Storer, 1925). The tadpole is fairly large, 2 7/8 

 inches (72 mm.), its body flattened, the tail musculature wide for an 

 inch or more, then suddenly tapering, the tail tip rounded or spatu- 

 late. The crests are broader toward the tip than at the body. The 

 tooth ridges are 3/4 or 2/4. The period of development is 1 year, the 

 animal passing the winter as a tadpole. It transforms, during July and 

 August, at 7/8-1 1/12 inches (21-27 mm.). 



Notes: August 23, 191 7. Alta Meadows, California. In the pools 

 on the mats were plenty of Rana boylii sierrae. They stink like minks 

 or other weasels. /They are very slow. One can run a net under them 

 or put a net on the bottom in front and touch the back parts. They are 

 very yellow underneath. The species is almost through transforma- 

 tion. The larvae look on the venter somewhat like large toad tadpoles. 

 We found a few transformed individuals. 



"This subspecies was found to be abundant in the vicinity of a 

 fair-sized mountain stream which runs alongside the road from 

 Placerville to Lake Tahoe in Eldorado County, California, at a point 

 about 40 miles west of Lake Tahoe. There was very little vegetation 

 along the broad stream, which flowed moderately and with a depth 

 varying from one to three feet. The bed of the stream, easily seen 

 through the clear water, was essentially of stones, gravel and sand. 

 The frogs were usually resting at the water's edge, but they jumped 

 into the water and hid under stones as we approached. A number 

 were secured with the fingers after they had been pinned to the rocks 

 under which they were seen to take refuge or after they had been 

 trapped in some under-water crevice. 



"Mr. Oliver Millard has recently sent us a series of this form 

 which he collected in the Sierra Nevada Mountains along a tributary 

 of the north fork of the Stanislaus River at an elevation of 6,500 

 feet, 15 miles northwest of Calaveras, Calaveras County, Cali- 

 fornia." — (C. E. Burt and M. D. Burt, Nov. 19, 1929, pp. 432, 433). 



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