1917 1 Camp: An Extinct Toad from Rancho La Brea 



289 



North American toads (Bufo) can be placed in three divisions: 

 the americanus-lentiginosus-cognatus group with prominent angular 

 head crests ; the debilis-punctatus-alvarius section with crests low and 

 curved around the orbits and with broad fronto-parietals ; and the 

 boreas-canorus group with no cranial crests (except in old adults) and 

 with narrow fronto-parietals. It is to the latter division that the 

 present species seems to belong. Bufo -nestor differs from existing 

 Pacific Coast toads, of the forms related to B. boreas, in its wider, 

 flatter and more roughened fronto-parietals; longer and wider sphen- 

 ethmoid; stouter and posteriorly pointed parasphenoid ; flatter squa- 

 mosals; mere slender prootics; larger and more completely protected 

 brain-case. 



Other material, consisting of toad bones, doubtless of the above 

 described species, from locality 2051, Rancho La Brea, is as follows: 

 Fourteen vertebrae; 2 third, 1 fifth, and 4 ninth (sacral) ; one pelvis; 

 one ilium ; eleven femora ; twenty-four tibio-fibulae ; fourteen humeri ; 

 five radio-ulnae ; two complete and one fragmentary calcaneo-astragali ; 

 and one parasphenoid. In addition to the above, there is toad material, 

 from locality 2052, consisting of seven vertebrae: 1 third, 2 fourth, 

 1 seventh, and 2 ninth (sacral) ; one ilium; twenty-one femora; thirty 

 tibio-fibulae ; twenty-two humeri ; six radio-ulnae ; two complete and 

 two fragmentary calcaneo-astragali; and one parasphenoid. 



The parasphenoid from locality 2051 agrees with the type in ratio 

 of wing width to total length and in the pointed character of its 

 posterior tip. It differs in the above characters from the parasphenoid 

 from locality 2052 and from B. b. boreas and halophilus. 



Femora from localities 2051 and 2052 and of existing bo-re us are 

 almost indistinguishable. The largest are only about two-thirds the 

 length of a frog femur of medium size (Rana draytonii) , and all bear 

 larger epiphyses than do corresponding bones of a specimen of spade- 

 foot (Scaphiopus h. kammondii) at hand. The sigmoid curvature is 

 more pronounced than in Bufo woodhousii. The smallest femur, from 

 locality 2052, is much shorter than in Hyla arenicolor, but is thicker 

 through the shaft. The largest specimens are longer than in any 

 B. b. halophilus at hand and approach B. alvarius, but differ from 

 that species in the more flattened character of the median ridge. A 

 femur at hand of B. b. boreas from Vancouver Island is longer than 

 any specimen from Rancho La Brea. 



Seventeen humeri from locality 2052 do not differ greatly except 

 in size from existing B. b. halophilus. The longest is one-fourth 



