COPE.] PALEONTOLOGY MIOCENE PERIOD. 465 



tensis of Leidy, from the bad lands of Dakota, obtained by Dr. Haydeu 

 in 1866. These species are allied to both the hedgehogs and the teurecs 

 of Madagascar, and represent the larger forms of the order. A third 

 species of the same group was found by the writer, viz, the Isacis cani- 

 cuius. But the greater number of species discovered are of smaller size, 

 and belong to families of which no representatives had been previously 

 known in the American Miocene. Herpetotherium, Cope, embracing the 

 greatest number of species and individuals, is possibly a member of the 

 Tal/pidce, and presents aflBnities to the European genus Talpa^ or the 

 true moles. Domnina, Cope, and probably IJmhassis, Cope, present 

 affinities to the Soricidw, so far as known. As elsewhere, the species 

 are most frequently represented by rami of the mandible, often with 

 beautifully-i)reserved dentition ; but portions of (irania are occasionally 

 found. Those of the latter in my possession are referable to three 

 species. One of them fortunately supports both mandibular rami, and 

 furnishes the entire dentition of the Herpetotlierium fugax^ the sujDerior 

 incisors only being wanting. Another consists of a very elongate and 

 compressed muzzle, with which a cranium with base of muzzle may be as- 

 sociated. They are described provisionally under the head of Bomnina. 



The generic types differ as follows : 

 * Inferior molars (except rarely the posterior) similarly composed : 



Serpetotheriwn, Cope. Dentition : I., -^ ; C, i ; P. m., f ; M., ^. Last 

 inferior molars nearly -similar to the others, which have the poste- 

 rior pair of tubercles and the anterior one distinct ; inferior canine 

 large,' followed immediately by premolars. 

 Umbassis, Cope. Inferior molars without anterior cone ; the ante- 

 rior lobe elevated, triangular in section ; posterior tubercles conic ; 

 last molar similar. 

 Domnina, Cope. Inferior molars three, with the outer posterior 

 tubercle a crescent, like the outer anterior ; the inner posterior a 

 cone ; anterior forming a sectorial edge with outer ; last molar 

 smaller, consisting of one crescent and a heel ; molars increasing 

 in size anteriorly with anterior cone. 

 ** Inferior molars dissimilar, tubercular, and sectorial: 



Isacis, Cope. Last three molars with cross-crests ; the one preced- 

 ing with an anterior conic cusp and two median ones, with a broad 

 heel, which supports a cusp. 

 The total number of the species of Inscctivora obtained by the expe- 

 dition of 1873 is as follows, all of them being at the time new to science : 



Herpetotherium, Cope 5 



Emhassis, Cope 2 



Domnina, Cope 3 



Isacis, Cope 1 



11 

 HERPETOTHERIUM, Cope. 



Paleontological Bulletin, No. 16, 1873, p. 1.— Synopsis of New Vertebra ta from the Ter- 

 tiary of Colorado, p. 4. 



This genus is more nearly allied to the existing genus Talpa of the 

 Palearctic region than to any existing North American form, so far as 

 dental characters are conclusive. The number of niolax teeth is greater ; 

 thus ff in the extinct to || in the recent genus.* If the inferior cani- 



* Tbo dental formula given for this genus (Synopsis New Vertebrata, &c., p. 4) em- 

 braces the figures, incisors f. This is a typographical error for L. I did not have 

 opportunity of reading the proofs. 



30 G- s 



