VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 223 



from the apex of the ectocone, equals half the length of the crown. The grinding 

 surface of the heel is partly vermiculate, partly tuberculately rugose. The middle 

 of the grinding face anterior to the heel is occupied by a series of low tuberosities, 

 as in the first true molar. 



Of the inferior incisors the crown of the external has a strong external space, 

 which is lacking in the others. Its external face is longer, while the internal face 

 is shorter than in the others. All have a shallow longitudinal groove of the external 

 face. The inferior canine is without the keel of the posterior face of the crown. The 

 premolars are all small, and the fourth only has two roots. All are isolated by 

 short diastemata, excepting the fourth which is close to the first true molar. The 

 crown of the first is oblique ; of the second and third low conic. The fourth has a 

 low median cusp with a short production of the base in front and a longer one 

 behind, with a low median ridge. The sectorial displays a form like that of the 

 South American forms and unlike those of Eurasia, in the simple character of the 

 metaconid. The length of the blade, or protocono-paraconid, is two-fifths that of 

 the crown. The metaconid is low and is opposite the posterior part of the proto- 

 conid. Immediately posterior to it, separated by a valley, is the small ectoconid. 

 The external part of the heel is occupied by the large hypoconid, which is separated 

 from the protoconid by a small supernumerary tubercle. I have found this tubercle 

 present in the six sectorials' of the different individuals of the collection. 



Of the second inferior true molars there are ten in the collection, which pertain 

 to nine individuals. Four of these are little or not worn. The grinding face is 

 contracted transversely to a diameter less than that of the base of the crown. The 

 external base is more swollen than the internal, while the internal side of the crown 

 is most obliquely contracted at its superior portion. Only two cusps can be identi- 

 fied, the protoconid and the metaconid, which are connected by a transverse ridge, 

 notched at the middle, and of which the metaconid is considerably the most elevated. 

 There is a well-developed area which represents the trigon, but it develops no para- 

 conid and no other cusps. The keel is about twice the length of the trigon and, 

 though its margins are feebly notched at intervals, it develops no cusps or tubercles. 

 There are traces of low obtuse tubercles along the middle of the grinding surface as 

 in the superior molars. The grinding face in general is shallow concave. Its 

 anterior and posterior borders are little contracted from the base. The last inferior 

 molar is shorter in relation to the penultimate than in U. arctos and U. maritimus, 

 resembling in this respect Tremarclos ornatus. Its crown is a little longer than 

 wide, and is broadly rounded posteriorly, though narrower than anteriorly. The 

 grinding face is a little contracted and is slightly concave, and there is an emargi- 

 nation of the external border a little posterior to the middle. The surface is fully 

 tubercular, coarsely anteriorly and finely posteriorly. 



The enamel of all the molars is vertically rugose, except where worn by pro- 

 longed use. The rugosities are fine or rarely coarser ridges. 



Two considerable parts of mandibular rami exhibit all the characters except 

 the apex of the coronoid, which is lost from both. The ramus is moderately slender, 



