8 COPE. [Vo. II. 
connecting crest. And from the quinque- and quadrituber- 
cular types of molar crown, the various specialized types of 
the ungulates have been derived. 
Considerable significance, therefore, attaches to the question 
as to whether the superior true molars of Homo sapiens are 
quadritubercular or tritubercular. The inferior molars are 
also either quadritubercular or quinquetubercular; but less 
significance attaches to this modification than to that of the 
superior true molars. This is owing to two facts; viz., the 
fifth tubercle is not the anterior inner which completes 
the anterior triangle of the primitive inferior molar, but is 
a median posterior, such as is not uncommon in mammalia 
of Puerco and Eocene age; and second, because this tuber- 
‘ cle is of quite small size, and is therefore more liable to 
variation from insignificant causes. 
In the nearest allies of man, the anthropoid apes, the supe- 
rior true molars are quadritubercular, the posterior internal 
tubercle of the last or third molar being usually smaller than 
in the other molars in the chimpanzee. The inferior molars 
are quinquetubercular, in the human sense, the gorilla not 
infrequently adding a sixth lobe on the external posterior 
margin of the crown. The molars of both series are quad- 
ritubercular, with an occasional posterior fifth in the inferior 
molars in the Cercopithecidz and Cebidz, excepting the 
genus Pithecia of the latter, where the superior molars are 
tritubercular. The superior molars of the Hapalidz are tri- 
tubercular. In the Lemuridz the second and third, and fre- 
quently the first, superior true molars are tritubercular. In the 
Tarsiidze the superior true molars are tritubercular throughout. 
The superior molars of the extinct lemuroids differ, like those 
of the recent forms. Thus, in Adapis and its allies they are 
quadritubercular, but in Necrolemur they are tritubercular. In 
Chriacus (whose reference to the Lemuroidea is uncertain) they 
are tritubercular, as is the case, also, with Indrodon. In Anap, 
tomophus they are of the true tritubercular type. This is the 
genus of Lemuroidea, which in its dental character most nearly 
approaches the anthropoid apes and man. I have elsewhere? 
pointed out that the formula is I. - Cc. ; Pm. =; M. ; The 
canines are small, and there is no diastema in either jaw. 
1 Report U. S. Geol. Survey, Terrs., F. V. Hayden, Vol. II1., 1885, p. 245, Pl. 
xxv. fig. 10, and Pl. xxive. fig. 1. 
