178 0. C. Marsh — Cretaceous Mammalia. 



Stagodon nitor, gen, et sp. now 



The present genus is based on a number of molar and pre- 

 molar teeth, some of which were found together, but may per- 

 tain to separate individuals. The striking character of all the 

 molar teeth secured is the resemblance of their crowns to a drop 

 of viscous fluid, and this is shown in the figure of the type 

 specimen, Plate VII, figures 22-25. This is probably a lower 

 molar, as it has but two fangs. 



The premolar represented on Plate VII, figures 17-21, has 

 the same general rounded character, but the form shows its 

 position. This tooth has a portion of the maxillary attached 

 to it. It represents a larger species, which may be called 

 Stagodon tumidus. 



These remains evidently represent a distinct family, which 

 may be called the Stagodontidce. They are from the Laramie 

 of Wyoming. 



Platacodon nanus, gen. et sp. nov. 



A number of peculiar teeth, very diminutive in size, have 

 been found in the Laramie. Although evidentlv mammalian, 

 it is impossible at present to make out their exact affinities. 

 The three teeth represented on Plate VIII, figures 4-12, were 

 found together, and apparently form a series from one jaw. 

 They may be considered as the type. They resemble some- 

 what, in form, the flattened molars of Chrysochloris, but they 

 are more probably premolars. Their main features are well 

 shown in the figures. They indicate an animal about as large 

 as a shrew, and are from the Laramie of Wyoming. 



Oracodon anceps, gen. et sp. nov. 



A number of peculiar teeth, mostly premolars, represent a 

 very distinct genus, the affinities of which are doubtful. The 

 type specimen is shown on Plate VIII, figures 13-16. It is 

 apparently a lower premolar from the right side, and was 

 implanted by two strong fangs. The crown consists of one 

 main cone, with two small tubercles behind, placed trans- 

 versely, and three in front. Two of the latter are in the same 

 row with the main cone, and one smaller is on the inner side. 

 The top of the main cusp is worn, mostly on the outside. 



This specimen is from the Laramie of Wyoming. 



Allacodon lent us, gen. et sp. nov. 



The present genus, which appears to be nearly allied to 

 Attodon of the Jurassic, is represented by a number of teeth, 

 several of which were found together. The upper molar shown 



