210 VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 



the outer. In worn teeth this groove is continued into the grinding surface of the 

 crown, without interruption from the enclosing enamel. The form of this surface 

 is then an oval notched on the inner side, and rounded or slightly truncated on the 

 outer. The palatine face is but partially preserved, and is considerably wider in 

 proportion to the diameter of the teeth than in Lepns sylvaticus. 



Measurements. 



mm. 

 Length, crown of four consecutive molars; 6.1 



Width, crown one molar; 2.1 



Width, palate between bases of molars; 10.0 



EDENDATA. 



MYLODON Owen. 

 Mylodon? harlanii Owen. 



A single ungual phalange of a Mylodon, perhaps of this species, was found by 



Mr. Wheatley. No trace of the genus has been found since that time. 



MEGALONYX Jefferson. 



Remains of this genus of Megatheriida3 are very abundant in the Port Kennedy 

 fissure. Twenty-eight individuals are represented by fragmentary skulls and jaws. 

 In one of these the skull is nearly entire, but is crushed ; another consists of the 

 greater part of the lower jaw with teeth ; in others little but the jaws remains ; in 

 one the greater part of the cranium is present without jaws. Besides these there 

 are one hundred and thirty separate canine-molar teeth, and perhaps twice as many 

 separate molars. These jaws and teeth represent at least eighty-one individuals, 

 and probably more. To these must be added fourteen individuals contained in the 

 Wheatley collection, making a total of ninety-five animals. Bones of the skeleton 

 are very abundant, but owing to the wetness of the cave deposit, only the harder 

 ones have been preserved, with some exceptions. Thus the most numerous elements 

 in the collection are carpals, tarsals, metapodials and phalanges. 



The abundance of material enables me to determine the number and characters 

 of the species more exactly than heretofore. I reaffirm the conclusion I reached in 

 1871, after studying the Wheatley collection, that Megalonyx jeffersonii Cuv., as 

 described by Leidy, left no remains in the Port Kennedy fissure. By far the greater 

 number of individuals belong to a rather smaller species, M. wheatleyi Cope, while 

 a still smaller one, M. torlulus Cope, was not uncommon. A single tooth, so far, 

 represents a third species of the size of M. wheatleyi, M. loxodon Cope. 



The canine-molar teeth of these species all present characteristic and recogniz- 

 able peculiarities, while the true molars differ rather in size than in form. The last 

 superior molar, however, differs considerably in form. In some individuals it is 

 triangular in section ; in others the section is a transverse oval. All intermediate 

 forms occur in M. wheatleyi. The inferior canine-molars are little or not curved, 

 while the corresponding superior teeth are much curved anteroposteriorly. The 

 internal bulge is not so conspicuous in the inferior canine-molars as in the superior. 



