MERRIAM: THE FAUNA OF RANCHO LA HKKA 229 



with the carnassial. The most noticeable peculiarity of this tooth is the reduc- 

 tion of the hypocone, which is smaller than in any of the Recent North 

 American wolves. The short ridge of the hypocone never extends forward 

 around the base of the protocone to join an anterior basal ridge as commonly 

 occurs in the Recent wolves. The extreme median side of the hypocone fre- 

 quently does not extend farther toward the median line than does the base of 

 the protocone. The protocone, paracone, and metacone are not materially dif- 

 ferent from the corresponding tubercles of the modern wolves, though the bases 

 of the paracone and metacone often tend to be relatively thick transversely. 

 A distinct metaconule is always present and a small protoconule is usually 

 developed. 



M L ' is relatively small compared with the sectorial, and is usually also small 

 compared with M 1 . In specimen 10856 its dimensions are practically identical 

 with those of a Recent C. pambasileus which has a much smaller skull, and 

 in which the other teeth are smaller. The principal difference between the 

 form of this tooth seen here and that in the Recent wolves is found in the 

 uniformly smaller size of the hypocone. In some instances the anterior end 

 of the hypocone crest does not extend forward as a ridge of the cingulum along 

 the anterior side of the tooth. 



Inferior Dentition. In most specimens observed the incisors are thrown 

 considerably out of alignment by lateral crowding, I 2 being set back at least 

 as far as L, while the posterior border of L, is nearly even with the anterior 

 border of L. 



I 3 has much the same form as in the large Recent Alaskan wolves excepting 

 that the lateral lobe tends to be relatively small. 



Fig. 5. Canig dirus Leidy. Superior view of inferior premolar and molar series, no. 10834, natural size. 

 Rancho La Brea Beds. 



In the inferior canine the sharp anterointernal ridge which marks the 

 enamel of this tooth takes a course somewhat different from that in the Alaskan 

 C. pambasileus. In passing forward from the posteroinferior region of the 

 inner face of the tooth it does not rise as rapidly as in the Recent Alaskan 

 wolves, but extends forward to a point near the anterior side of the tooth and 

 only a few millimeters above the base of the enamel before it takes a direct 

 upward course toward the apex of the crown. The angle formed by the sharp 

 upward turning of this ridge is higher up on the side of the tooth, and conse- 

 quently more obtuse in the Recent Alaskan forms. In a specimen of C. latrans 

 from Manitoba this enamel ridge is closely similar to that in C. dirus. 



Pi (figs. 5, 6, and 7) tends to be rather small compared with P 2 . A faint 



