598 The American Naturalist. ~ [July, 
premolar. . . . Char. gen— 
Fourth premolar with a com- 
pressed antero-posterior edge, 
which is studded with denticles ; 
sides without ridges. Posterior 
molar rather small; crown with 
tooth subsequently described 
and the fragment of a humerus 
are evidently mammalian, but 
without a name.” — American 
Journal Science and Arts, loc. 
ctt., p. 82. 
three longitudinal series of tu- 
bercles, of which many have 
crescentic sections.” — AMERI- 
CAN NATURALIST, loc. cit., p. 830. 
It is very clearly stated by Prof. Cope in the above description 
and context that the first tooth—. e., the true molar—is the one | 
upon which the mammalian determination is 
based; and that the second tooth—z. e., the 
premolariform one—would have been considered 
— Menis- Yeptilian except for its association with the first. 
ee ere ws This was clear to Lydekker, Lemoine, Osborn, 
inferior molar; x2. and all subsequent writers, being repeated later 
with emphasis by Prof. Cope (Amer. Nart., July, 1884, p. 693). 
Previous Literature and Description—There are obvious advan- 
tages in not consulting and referring to previous literature. It 
leaves the mind of a writer unprejudiced by previous opinions, 
and moreover lends to a contribution a quality of independence 
and originality. On the other hand, it deprives him of the 
benefit of past careful and laborious studies, and leads him into 
errors which might easily be avoided. 
In case of the papers under review, previous literature has 
apparently escaped the attention of the author, except in the 
matter of nomenclature. The result is that some well-known 
principles which govern the extremely complex and confusing 
dentition of the Multituberculates are left out of consideration 
entirely, as well as some of the main characters of the den- 
tition of the Mesozoic mammals in general, and some char- 
acters which enable us to distinguish between the teeth of 
mammals and those of reptiles and fishes. As regards the Mul- 
tituberculates (Allotheria), it is now well known that their teeth 
show the eee characters : 




