1921] Frick: Faunas of Bautista Creek and San. Timoteo Canon 363 



development of all teeth anterior to the premolar series; (i) the 

 bilobed, double fanged, first tooth of the cheek tooth series versus a 

 greatly reduced tooth in C. hesternus (Pg usually absent) ; (5) the 

 relatively large size of the outer incisor of the lower jaw versus the 

 first incisor as seen in C. hesternus. 



The dental arrangement of the lower jaw is very similar to that 

 occurring in Pliauchenia spatula, as figured by Cope, in the relative 

 proportions of the posterior diastemata, the position of the mental 

 foramen, in the absence of a well defined diastema between the canine 

 and outer incisor, and in the proportions of the first cheek tooth. The 

 specimen, however, differs from Professor Copes type in its mvich 

 greater size and the accompanying marked development of its first 

 incisors and first premolars. The elongated muzzle, with its strongly 

 developed caniniform premolars in both the upper and lower jaw, 

 would scarcely seem to come within the limits of {Plianchcnia) 

 Megatylopus as defined by Dr. Matthew {op. cit., p. 396) : "The 

 second premolar absent in both jaws, the first retarded or absent . . . 

 the diastema behind P^ is rather short, and a much shorter diastema 

 intervenes between P- and the canine alveolus. This, with the general 

 proportions of the face indicates a much shorter muzzle than in P. 

 spatula.'' The anterior portion of the upper jaw of Megatylops gigas 

 is unfortunately unknown. The caniniform premolar of the specimen 

 is apparently much more robust than the corresponding tooth of 

 M. gigas that is described as "a good sized tooth, with pointed spatu- 

 late crown, but which appears retarded in development." Lower 

 jaws referred by Dr. Matthew to M. gigas are said to show the absence 

 of P^, but P3, and P5 less reduced than in P. spatula. 



As suggested above, the remnant of the first cheek tooth might 

 represent siich a Pj as that of Cainelus, the fossil considerably resem- 

 bling this genus in general character. The specimen, however, differs 

 from the Camelus americanus/'^ based on a lower jaw from the Hay's 

 Spring Pleistocene, in the strength of the lower canine, which is weakly 

 incisiform in C. americanus , and in the much greater general size, 

 the present specimen measuring 150 mm. from incisive border to 

 cheek tooth series versus 114 mm. in C. americanus. The lower canine 

 of Camelus sivalensis of the late Indian Pliocene is well developed and 

 unseparated from the incisors, somewhat as in the present specimen, 



50 Wortman, Jacob L. The Extinct Camelidae of North America and Some 

 Associated Forma. Bull. Am. Mus. Nat. Hist., vol. 10, i)p. 133-134, 1898. 



