VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 199 



unworn tooth no division of the posterior fossa is visible. Wear exposes the fossa, 

 which is small and round and nearly median in position. 



If these characters indicate specific difference, there are two species in the Port 

 Kennedy collections. I am, however, not satisfied that such is the case, and must 

 see better material before reaching a conclusion. The tooth of the Wheatley 

 collection I thought at one time to indicate a species distinct from the common porcu- 

 pine, to which I gave the name of Erithizon cloacinum} One of the characters 

 which I assigned to it was that the external enamel inflection in E. cloacinum is as 

 deep as the internal in the vertical direction, while in E. dorsatum it is deeper. In 

 the Academy specimens the external inflection is not so deep as the internal, as is 

 sometimes the case in E. dorsatum also. The Port Kennedy molars are of the same 

 dimensions as those of the existing species. 



Measurements. 



Diameters of superior molar 



f anteroposterior; 76 



[ transverse ; 

 Incisor transverse diameter in front ; 55 



Two of the Port Kennedy teeth were found in immediate normal juxtaposition, 

 and probably belonged to the same jaw. They agree in their characters as above 

 described. The mandibular ramus is more robust than the average of the species, 

 while the molars are normal. One of the specimens includes four superior molars, 

 which are not different from the typical form. An inferior deciduous molar resem- 

 bles exactly that of E. dorsatum. 



SCIURUS Linn. 

 Sciurus calycinus Cope, Proc. Am. Phil. Soc, 1871, p. 86. 



Established on two imperfect rami of the under jaw, with the incisor and first, 

 second and third inferior molars in situ. The size approximates it to S. hudsonius, 

 and exceeds that of S. panolius. The form of the ramus, so far as visible, is not 

 unlike that seen in the same squirrel. The characters which distinguish it from 

 S. hudsonius, are chiefly to be seen in the molar teeth, especially the anterior. The 

 crowns of all are deeply cupped, and the triturating surfaces form anterior and 

 posterior bounding bands, which widen outwardly. The margin of the tooth is 

 elevated and entire, except externally, where the two usual low cusps are separated 

 by a deep notch. In S. hudsonius the interior and exterior margins are both 

 emarginate, each notch supporting a median cusp, thus forming three on each side. 

 The anterior molar exhibits this character still more strongly. Its crown is a cup 

 as wide as long, with high uninterrupted margin, except on the outer side, where it is 

 deedly notched. It has but two roots. In S. hudsonius this tooth has three roots, 

 is longer than wide, and has three marginal cusps on the inner and outer sides of 

 the crown. 



1 Proc. Am. Phil. Soc, 1871, p. 93, fig. 19. 



