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Universifjj of California Publications in Geology [Vol. 12 



projection. The presence of a shallow maxillary fossa is indicated by 

 a slight indentation above the canine. The lower jaw is more elongate 

 and is also apparently heavier and less constricted in the region just 

 anterior to the cheek teeth than is the usual case in the camels. 

 ]\Iental foramina occur below the posterior border of the first pre- 

 molar, and the symphysis extends slightly posterior to the same. 



Upper jatc. — Incisors one and two are absent, though the former 

 position of I- is suggested by a slight swelling of the alveolar border. 

 The three anterior teeth are all large, strongly recurved, and canini- 

 form. They are separated from each other and the cheek tooth series 

 by progressively lengthening diastemata, which are deeply arched. 

 The caniniform incisor is exceedingly stout, equalling the canine at 

 the alveolus in anteroposterior diameter. The tooth, however, has 

 been considerably ground down through attrition with the inferior 

 canine and with the first incisor, which has worn a groove deep into 

 its anterior surface. The canine is long, stout, and furnished with 

 sharply compressed anterior and posterior cutting edges. The first 

 premolar is but little lighter than the canine and closely resembles 

 it in form. 



Lower jaiv. — The incisors are strong and spatulate, increasing in 

 size from the transversely compressed outer to the heavy, elongated 

 inner incisor. The posterior edge of the third incisor has been 

 flattened through contact Avith the upper canine. A large, suberect 

 canine directly adjoins the incisor series; its anterior half has been 

 ground away by the superior caniniform tooth, leaving the semblance 

 of a slight diastema. The lower canine is less curved than the upper 

 tooth. The first premolar is somewhat compressed, with remarkably 

 sharp cutting edges, and is strongly recurved and caniniform. In 

 anteroposterior alveolar diameter this tooth equals the preceding. The 

 remnant of the first unit of the lower cheek series, in the form of 

 anterior lobe and alveolus, indicate a narrow but well developed, two- 

 lobed, and double rooted tooth. 



Position. — x\.s the present grouping of the camels is so considerably 

 based on the reduction or the retention of the premolars, the proper 

 interpretation of the jaws and the phylogenetic relation.ship of the 

 species in question rests largely on the correct interpretation of the 

 remnant of this first cheek tooth. The specimen is evidently a pre- 

 molar, being compressed rather than quadriform. The tooth, however 

 could not represent the double rooted, unreduced of the genus 



