240 VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 



have been referred to other genera excepting M. catocapis Cope of the Loup Fork 

 bed of Nebraska, which was only provisionally referred to it. Two saber-tooths of 

 the North American Plistocene, described by Leidy, from Florida and Texas, belong, 

 so far as their cranial structure indicates, to the genus Smilodon. The type of 

 this genus is S. neogceus Lund, which is found in the Pampean bed of South 

 America, probably of Plistocene age. In this genus the humerus lacks the entepi- 

 condylar foramen, which is common to all other members of the Felidae, and the 

 post-tympanic and post-glenoid processes are fused below the auricular meatus. 



Two species of saber-tooths have been found in the Port Kennedy deposit, but 

 in neither of them is the posterior part of the cranium known. The distal part of 

 the humerus of one of them at least is probably known, and this presents the entepi- 

 condylar foramen. With this evidence in hand I have no other course but to refer 

 the species to the genus Maclicsrodus, provisionally. 



In Smilodon fatalis Leidy of Texas, the superior sectorial has a large pre- 

 anterior lobe as in S. neogceus of South America, which is rudimental in Machcv- 

 rodus gracilis of the Port Kennedy deposit, in which respect it agrees with the 

 species of Machcerodus. In S. floridanus the canine is much less compressed than 

 iu S. gracilis. The Port Kennedy species differ as follows : 



Larger ; pm-^, absolutely smaller, one-rooted ; m T , larger ; M. gracilis Cope. 



Smaller ; pm^, larger, two-rooted ; my, smaller ; M. mercerii Cope. 



Neither of these species attained the dimensions of Smilodon neogceus of Brazil, 

 but M. gracilis equalled the lion or Machcerodus cnltridens of Europe, while 

 M. mercerii had apparently the size of the jaguar. 



Mach^rodus gracilis Cope (PI. XX, fig. 1). 



Smilodon gracilis, American Naturalist, 1880, p. 857; I 'roc. Acad. Nat. Sci. Phil., 1895, p. 448. 



This saber-tooth is represented in the collection of the Academy by cranial frag- 

 ments and dentition of four individuals, and by a great many bones and fragments of 

 bones principally of the limbs and feet ; and in the Wheatley collection by a superior 

 canine which lacks most of the crown. The most important specimen consists of 

 that part of the cranium and mandible which supports the dentition, which is 

 entirely preserved as to the incisors, and on the left side as to the remaining part. 

 The superior canine and the lower jaw are somewhat crushed. Nothing remains 

 of the skull posterior to the maxillary bone. A separate superior canine tooth was 

 found about eighteen inches from the skull fragment, which belongs to another indi- 

 vidual. The third specimen is the one which was described at the second reference 

 above given. It includes several teeth found near together but separated from the 

 skull. They are a superior canine minus part of the crown, one and part of another 

 superior sectorial of opposite side ; a superior third premolar ; and a first inferior 

 premolar less certainly referable to it. A fragment of lower jaw with two molars 

 found near the same time and place formerly referred here, belong to Uncia inex- 

 pectata. The fourth individual is represented by a part of the right mandibular 

 ramus, which supports the sectorial tooth. 



