23 



Char, specif. — The last premolar is longer than any of the molars. 

 There are no cingula on the molars, but the transverse crest from one 

 of the tubercles descends to the side of that opposite to it, along- the 

 end of the crown ; enamel smooth ; ramus of the jaw rather elongate. 



Measurements. 



M. 



Length of bases of six molars 0.0250 



Length of bases of true molars 0120 



Length of bases of first true molar 0040 



Width of base of first true molar 0032 



Length of basis of last premolar 0052 



Width of basis of last premolar 0030 



Depth of ramus at last premolar 0090 



This animal was about as large as the (domestic cat. 

 ISACis CANICULUS Cope, Paleoutological Bulletin, No. 16, p. 3. 



This genus is intermediate between the Lepiictis and Ictops of Leidy, 

 so that either one genus must be recognized or three. The superior 

 molars have the some constitution, with specific resemblances to Ictops 

 dacofensis ; but the last premolar, while possessing an internal cusp, as 

 in that genus has but one, a narrow, conic tubercle on the outer side, as 

 in Leptictis. 



Herpetothekium fugax Cope. 



The dental formula given for this genus (synopsis New Vertebrata, 

 &c., p. 4) embraces the figures Incisors |. This is a typographical error 

 for I". (I did not have opportunity of reading the proofs.) 



HoPLOPHONEUS OREODONTis Copc ; Macluierodus oreodontis Cope; 



svnopsis New Yert. Colorado, 1873, p. 9. 



Char, r/ew.— Dental formula of mandible : L 3 ; C. 1 ; P. M. 2 ; M., 2. 

 Superior canine greatly developed ; end of mandible expanded and 

 thickened to protect it. 



This is simply Machaerodus, with a tubercular molar, as in D'mictis. 

 The dental formula is the same as that of Bunaelurus, but the latter 

 probably has the character of Fells in its anterior dentition, though this 

 is not absolutely certain.* 



Cliar. specif. — The species was established on a young individual 

 ■with part of the temporary dentition remaining. A jaw of an adult 

 furnishes additional characters. The first premolar (the third) has two 

 roots, and is as large as the second, instead of being smaller, as in 

 Machaerodiis primaevus. The second (fourth) has a prominent anterior 

 basal tubercle, as in the last-named species, but which is, according to 

 Leidy, wanting in Dinictis felina. The anterior angle of the mandible is 

 not produced downward so much as in the Machaerodiis., but is more as 

 in Dinictis felina, vrith which the present species agrees nearly in size. 



PoiiBROTHERiUM HALLTi. Protomertjx halUi Leidy, Anc. Faun., Nebr., 



&c., p. 160. 



This species agrees closely with P. vilsonii in dental characters, dif- 

 fering only in the rather larger size, so far as the portion of the jaw of 

 the type furnishes indication. 



* One 01' the other of these genera may perhaps be found to be the AelurogaJe of Del- 

 fortrie, but I have not j-et seen its diagnosis. 



