Mylodon harlani, from Rock Creek, Texas. 339 



head and the inflation of the muzzle. In several of the Cali- 

 fornia specimens the teeth have fallen from the sockets, the 

 study in such cases being restricted to the alveolar outlines. 

 The series arranges itself as follows : 



1. Four skulls with four teeth on both sides. 



2. Six skulls with four teeth on one side and five teeth on 

 the opposite side. 



3. Nine skulls with five teeth on both sides. 



"The superior dentition varies, therefore, from four to five 

 teeth on each side ; and this variation appears to be independ- 

 ent of the age of the individual. It follows from the variable 

 presence of the first tooth, that it is the second superior tooth 

 which is the largest of the series. Upon the presence of the 

 first superior tooth depends, also, the nature of occlusion with 

 the first inferior tooth. 



"The fourth inferior tooth, in a series of five lower jaws, 

 is most distinctly trilobed in an individual of the first group. 

 The tooth appears slightly less trilobed in individuals of the 

 second and third groups, and may be two-lobed in the last 

 group. 



"Judging from the variation in the large series from Ranch o 

 La JBrea, the form described by Brown, as well as the remains 

 from the asphalt deposits, should apparently be placed in the 

 genus Mylodon." 



Stock goes on to say that the inferior dental series of several 

 mandibles from Rancho La Brea bears a close resemblance to 

 the type specimen of M. harlani. 



Morphology. 



The specimens under consideration represent three individuals 

 of approximately equivalent size and a fourth much smaller 

 animal. They are known respectively as catalogue numbers 

 10264-10267 of the Peabody Museum fossil vertebrate collec- 

 tion, of which 10266 is perhaps the largest and 10267 the 

 smallest, but the reference of all the bones to their respective 

 numbers, which is based alone upon difference of size, is not 

 without question. The elements represented collectively are 

 skull and jaw parts, about twenty-seven vertebrae, ribs, one 

 complete pelvis, two more sacra, fragments of the ilia, three 

 femora, one humerus, two tibiae, three astragali, one calcaneum, 

 one radius, two ulnae, four scapulae, carpal and foot bones, etc. 



Axial Skeleton. 



Skull. 



The elements represented are the complete occiput with 

 both condyles, the palate to the inner margins of the dental 

 alveoli of the four posterior molars, part of the left squamosal, 



