308 University of California Publications in Geology [Vol. 7 



available in the palaeontologic laboratory furnish for the first 

 time a satisfactory basis for comparative study of the skull and 

 dentition of our American Pleistocene camels. In advance of an 

 investigation of the entire representation of the skeleton the 

 following descriptions are presented. A discussion of the 

 skeleton will be furnished after completion of the excavation 

 work, when all materials of this group can be brought together 

 for more satisfactory study. 



SKULL 



The skull in specimens 20040. 20028, and 20049 approximates 

 the size in that of the Bactrian camel. The general outlines 

 resemble Auchenia more nearly than ('a nidus. In superior view 

 (figs. 1 and -1), the slender rostral region tapers more gradually 

 toward the anterior end than in Camelus, and in this respect 

 resembles Auclu nia. The frontal region is quite distinctly convex 

 transversely, with no median depression, and in this character 

 differs from the specimens of both Auchenia and Camelus avail- 

 able for comparison. The orbits are situated relatively far back, 

 the anterior border being situated above the last superior molar. 

 The basicranial and basifacial axes are nearly parallel, as in 

 ( '<im< lux. 



The nasal elements are long and narrow, the posterior ends 

 are separated by a wedge of the frontals, but the outer borders 

 do not spread widely as in Auchenia and Camelus. The anterior 

 ends of the nasals are in broad contact with the premaxillaries, 

 as in Auchenia. The nasals are relatively longer and narrower 

 than in Auchenia, and the notch for the posterior border of the 

 anterior nasal opening is not behind the posterior end of the 

 premaxillaries. In Auchenia the posterior ends of the pre- 

 maxillaries do not extend as far back as the posterior border of 

 the anterior nasal opening. The ends of the nasals project 

 anteriorly beyond the superior border of the premaxillaries. 



A characteristic feature of the Rancho La Brea specimens is 

 the presence of a large, deep fossa near the upper margin of each 

 maxillary above the fourth premolar (fig. 5). The inferior 

 region of this fossa is not sharply marked. The upper wall of 



