VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 209 



LEPUS Linn. 

 Remains of this genus are abundant in the deposit but I can only refer them 

 to a single species. 



Lepus sylvaticus Baclim. 



Some fifty individuals are represented by the specimens in the Academy's col- 

 lection. These differ a little among themselves in the form of the grooves on the 

 anterior face of the pm.- 3 -, and in dimensions. I have found no characters by which 

 to separate them from the species now living in the same region. The characteristic 

 post-frontal region is, however, not present in any of the specimens, nor the ascending 

 ramus of the lower jaw. The anterior premolar resembles that of L. sylvaticus 

 rather than that of L. americanns. 



Portions of crania of six individuals occur in the Wheatley collection. The 

 palatal surface of one is exposed, and is longer in relation to its width than in a 

 recent example. Thus in the former the length enters the width between the two 

 anterior alveoli 1.2 times ; in the latter 1.6 times. In Prof. Baird's figure it enters 

 1.4 times. Some of the specimens are smaller, some larger than the average of our 

 recent ones. One of them had an oval mass of carbonaceous matter in its mouth, 

 probably the remains of its unswallowed vegetable food. 



LAGOMYS Cuv. 

 Molars similar to those of Lepus, rootless, with crowns transverse to the axis 

 of the series, all simple ; masticatory surface not divided by median ridge, enamel 

 boundary emarginate on the inner side. Number in maxillary bone ? four. 



Lagomys palatin'us Cope. 



Praotherium palatinum Cope, Proc. Am. Phil. Soc, 1871, p. 94, fig. 20. 



This rodent is represented by the palatal region of the cranium of one indi- 

 vidual, with four superior molar teeth of each side in position. The latter diverge 

 symmetrically, probably in consequence of pressure. But a small part of the palatine 

 surface is preserved. The normal number of teeth is uncertain, but the anterior 

 tooth is known from its relation to the fragments of maxillary bone and perhaps 

 zygomatic arch. It resembles the three molars which follow it. Behind the fourth 

 no trace of tooth or bone could be found on exploring the matrix, though the latter 

 was unbroken, hence it is possible, though not certain, that there were none. 



The genus differs from those of the Geomyinae of Baird, in the simplicity of 

 the first molar. The wide palate and narrower zygoma, as well as the forms of the 

 teeth, are those of the rabbits, but it differs from the two genera, Lepus and Lagomys, 

 in the identity of structure of the first molar with the others, and the absence of an 

 enamel band dividing the triturating surface of each of them. In some of the teeth 

 a trace of the dividing lamina is visible, but does not appear to have been elevated 

 into a crest of the grinding surfaces. 



In specific characters, this rodent differs from our rabbits in its small size and 

 in having the molars deeply longitudinally grooved on the inner face, and not on 



27 JOUEN. A. X. S. PHILA., VOL. XL 



