44 The American Naturatst. [January, 
eneral Notes. 
GEOLOGY AND PALEONTOLOGY. 
A Review of the Discovery of the Cretaceous Mammalia.’ 
The following is an abstract of a review of “ The Discovery of 
of the Cretaceous Mammalia,” presented to the Society of 
Morphologists, December 30th, 1890. The review is mainly an 
analysis of the types upon which the author bases his systematic 
classification of the collection of mammalian teeth and other 
parts from the Laramie beds. These mammals are provisionally — 
referred by the author to four mammalian orders and eight 
families, five of which are new to science. Sixteen new genera 
and twenty-seven new species are also proposed. e 
It appears that before accepting this system we must eliminate : 
1. The terms preoccupied by other authors. 2. The terms 
founded upon different parts of the same animal, and thus largely 
preoccupied by the author. 3. The terms founded upon i 0° 
fect or indefinite types. 4. The terms founded upon reptilian 
or icthyopsidan teeth. This may be expressed as follows: 
A. ALLOTHERIA. Sy en OS ae MULTITUBERCULATA, Cope. 
1. Cimolomide. 
Cimolomys gracilis. 
Cimolomys bellus. 
Cimolomys digona 
2. Cimolodontide. ; 2 
Cimolodon nitidus. eae se ie eames 7 sp 
Nanomys minutus. 
3- Plagiaulacide. 
Halodon sculptus. 
Halodon serratus. 
Halodon formosus. 
4 
! The Discovery of the Cretaceous Mammalia, O. C. Marsh, American Jo 
Science and Arts, Parts I. and IL., July and August, 1889. 
