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University of California Publications. 



[Geology 



of the tibialis anticus is higher up the shaft, and the outer toe much 

 higher above the middle toe. In all these respects the cave form resembles 

 the genus Bubo except that the characters of the foot are not determin- 

 able. The depressed region of the proximal end is very broad and open 

 in its excavation, the papilla of the tibialis anticus is lower, but is not 

 drawn out into a ridge as in Scotiaptex. The somewhat accentuated angle 

 on the exterior border just opposite the osseous bridge seems due in part 

 to a slight scar on the bone. 



On the whole, the relationships of the form seem to be decidedly with 

 Bubo rather than with Scotiaptex. 



Fig. 3. Scotiaptex nebulosa (Forster). Eecent. Tarsometatarsus, an- 

 terior face, approximately natural size. 



Fig. 4. Bubo sinclairi, n. sp. Tarsometatarsus, no. 7092, Pleistocene of 

 Potter Creek Cave, Shasta County, California. Anterior face, approxi- 

 mately natural size. 



Fig. 5. Bubo sinclairi, n. sp. Tibiotarsus, no. 9852, Pleistocene of 

 Samwel Cave, Shasta County, California. Anterior face, approximately 

 natural size. 



