290 University of California Publications in Geology [Vol. 10 



larger than the largest obtainable specimens of the existing forms and 

 one-fifth longer than in the gigantic B. alvarius, which, however, is a 

 short-armed species. These toad humeri differ from existing Rana in 

 the greater expansion of the proximal ends, less degree of separation 

 and lack of furrow ventrally (or posteriorly) between the middle 

 rounded part and inner or post-axial condylar ridge of the distal 

 end. Five of these seventeen humeri exhibit the cresta medialis of 

 the male ; the others, including the four largest, are probably from 

 females. Five humeri, from locality 2051, do not differ materially 

 from those of 2052, and existing species, except that they do not attain 

 such a great size as those from locality 2052. Two show only the 

 cresta medialis. 



Radio-ulnae from the two Rancho La Brea localities show no 

 perceptible differences in comparisons with specimens of B. b. boreas 

 and B. b. halophilus. 



Twenty tibio-fibulae from locality 2052 are very similar to speci- 

 mens of B. b. halophilus at hand. They are not so strongly curved 

 or so large as in B. alvarius, not so small as in B. punctalus, differ 

 from B. woodhousii in the plate-like character of the ventral part of 

 the proximal epiphysis, differ from Rana in the greater ratio of length 

 to breadth, and from SeapJiiopus in greater thickness. 



Seventeen tibio-fibulae, from locality 2051, are almost indistin- 

 guishable from those occurring at locality 2052. 



Portions of two ossa innominata from 2051 resemble examples 

 of B. b. boreas and halophilus in all characters but height of the 

 ilium at its widest part. The Rancho La Brea specimens, perhaps 

 referable to B. nest or, exhibit a higher, heavier ridge on this bone 

 (which approaches the condition found in some of the Ranidae), fur- 

 nishing better attachment for the powerful extensor, leaping muscles 

 in the hind legs. 



Two sacral vertebrae from locality 2052 are procoelous and similar 

 to B. b. halophilus and boreas, one is as large as in a specimen of B. 

 alvarius, another smaller than in the largest B. b. halejphilus at hand. 

 Tbe diapophyses are in each case strongly dilated. The angle the 

 anterior edges of the diapophyses would make with one another when 

 joined is less than 180 degrees. A sacrum from locality 2051 is small 

 and seems relatively thicker and narrower than the corresponding 

 bone in B. b. halophilus. 



The calcaneo-astragalus from locality 2051 seems to bear no dis- 

 tinctive peculiarities. 



