PALEOCENE MAMMALS OF CENTRAL UTAH GAZIN 9 



worn tlian the type, the posterointernal cusp is further divided for a 

 part of its height so that the inner row has five cusps instead of four. 

 Wear has obscured the posterior portion of the outer row so that 

 it is uncertain as to whether there were five or six cusps, and the 

 fornmhi may be 5 : 5 or 6 : 5. The tooth is slightly larger than the type 

 of C utahensis. 



The posterior portion of another Mi, No. 16211, shows a cusp divi- 

 sion suggestive of the formula 7:5 or possibly 6 : 5. The latter 

 tooth portion is about the size of the type and comes from the original 

 Dragon Canyon locality. 



An incomplete tooth portion, No. 16210, which has only four cusps 

 preserved, is relatively large and may be the anterior portion of Mi, 

 in which case it approaches in size small specimens of Taeniolahis. 

 However, it may be the posterior portion of an Mg of C. utahensis. 



a be 



Figure 2. — a, Taeniolahis sp., lower molar portion (U.S.N.M. No. 16172), occlusal view, 

 Wagonroad Paleocene, Utah; b, Catopsalis utahensis Gazin, Mi (U.S.N.M. No. 15757), 

 type specimen, occlusal view, Dragon Paleocene, Utah, c, C. utahensis. Mi (U.S.N.M. 

 No. 16185), occlusal view. Dragon Paleocene, Utah. All X 2. 



A right lower jaw. No. 16209, in the Dragon collection has both 

 Ml and M2 but unfortunately the teeth are checked and partially 

 obscured by an ironlike matrix. 



Material of Catopsalis is particularly rare, there being but about 

 three known specimens outside of the material herein described, and 

 one of these, an M2, the type of Catopsalis calgariensis from the 

 Paskapoo, has been lost, although a cast of it is in the collections 

 of the American Museum of Natural History. The other two, the 

 types of C. foliatus and C. fssidens, are lower dentitions from the 

 Torrejon. The material of C. utahensis though more than doubling 

 the number of specimens representing Catopsalis does not seem to 

 present any significant evidence as to the ancestral stages in the 

 development of this genus. It is interesting to note, however, that 

 C. utahensis, especially as represented by No. 16185 and No. 16210, 

 appears somewhat less distinctly removed from Taeniolahis than do 

 the Torrejon forms. 



The anteroposterior and transverse diameters of the type. No. 

 15757, are 12 (approximately) and 6.5 mm., respectively. In No. 

 16185 these diameters are 13 and 7.3 mm., respectively. 



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