;i.;| MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



PARAMYS ROBUSTUS Marsh. 



]•„,,. ■ m ,i~ii. Am. i. Journ. Sci. and Arte, iv, 1872, 218. 



One of the largesl of the known species of Paramys, bring "somewhat 



larger than the common Woodchuck {Arctomys monax Gmel.)". Described 



by Professor Marsh from "two lower molars" and "other less important 



remains". Lower Tertiary deposits of Grizzly Buttes and Henry's Fork, 



Wyoming. 



PARAMYS LEPTODUS Cope. 



Paramyt Irplcdus Corr, Pal. Bull. no. 12, 1873, 3. 



'•About the size of "P. delicatus Leidy, and P. robustus Marsh, bid with 

 smaller ineisors, which have little more than half the diameter of the same 

 tooth in those species. The molars have two anterior separate, and three 

 posterior contiguous cones, the median smallest. The anterior and posterior 

 of both sides separated by a deep excavation. The anterior tooth is peculiar 

 in its greater compression. The posterior tubercles are not separated, and 

 the anterior inner situate behind the outer, and connected with the posterior 

 inner by a concave ridge." Length of the molar series 221 mm ; antero-pos- 

 terior diameter 38 mm ; transverse 24"™. Described from a right mandibular 

 ramus with all the teetli preserved. South Bitter Creek, Wyoming. 



PARAMYS DELICATUS Leidy. 



Paramyt delicatus l.i idt, Proc. Acad. Nat. Sci. Pbila. 1871, 231 ; ADn. Rep. TJ. S. Geol. Surv. Terr, for 1871 

 (1872), 357 ; Extinct Vert. Fauna (Final Rep. U. S. Geol. Smv. Terr. vol. i), 1873, 110, 335, 

 pi. vi, figs. 23-25.— Cope, Pal. Bull. no. 12, 1873, 4. 



Size about one-fourth less than Arctomys monax. Length of the lower 

 molar series 0.75 of an inch ; antero-posterior diameter of the lower incisor 

 i >. 1 7 : t ransverse diameter 0.13. Eocene beds near Fort Bridger {Leidy), and 

 Blacks Fork, Southwestern Wyoming {Cope). Described and figured by 

 Dr. Leidy (/. c.) from two specimens sent to him by Dr. Carter, "consisting 

 of portions of the right and left sides of the lower jaw, containing most of 

 the molars and portions of the incisors". 



PARAMYS DELICATIOR Leidy. 



Paramyt deltcatior Ll idy, Proc Acad. Nat. Sci. I'hila. 1871,231; Ann. Rep. U. S. Geol. Surv. Terr, for is? 1 

 1872), 357; Extincl Vert. Fauna, 1873, 110,335, pi. vi, figs. 2(1, 27. pi. xxvii, figs. 16-18.— 

 Cope, Pal. Bull. do. 12, I-:::, I 



Rather smaller than the preceding, and collected by Dr. Carter from 

 the same locality. Length of the lower molar series 0.62 of an inch ; antero- 



