388 BULLETIN UNITED STATES GEOLOGICAL SURVEY. [Fol. Yi. 



of this species, and part of the skull and dentition of a second. The 

 characters may be briefly given as follows : 



Muzzle narrow and short, with small incisor and canine teeth ; inner 

 anterior basal lobe of superior sectorial very small. First tubercular 

 very large, sub triangular. Mandibular ramus shallow; the external 

 face not divided into two planes. Masseteric fossa less defined below. 



^LTJRODON WHEELERIANUS Cope. 



Canis ivTieelerianus Cope, Eeport Explor. Surveys W. of lOOtli Mer., Lieut. G. 

 M. Wheeler, IV, pt. ii, p. 302, PI. LXIX, Fig. 2. 



This species was abundant in Nebraska, though originally discovered 

 in New Mexico in the Loup Fork beds. It is a more robust animal than 

 the 0. saevus, and differs in various details. The skull was of about the 

 same size, viz., rather shorter, but stouter than that of the Canis lupus. 

 The characters are as follows : 



Muzzle longer ; canine teeth large ; external superior incisor nearly as 

 large at base of crown as canine. Anterior inner lobe of sui)erior sec- 

 torial well marked. Mandibular ramus deeper and thicker, the external 

 face in two planes, separated by a rounded angle. 



One of the marked characters of this dog is the very large third 

 superior incisor. In ^. saevus it is much smaller than the canine as in 

 most CanidcB. 



^LURODON HY^NOrDES Sp. nov. 



This dog is indicated by a fragment of the skull which includes the 

 right premaxillary, maxillary, and most of the malar bones, coossified. 

 The alveoli of all the teeth, except the I. 1, are present, and crowns of 

 all the molars, excepting the Pm. I and M. II. The animal is adult, 

 and rather aged. 



The external incisive alveolus is large, but not equal to that of the 

 canine. The latter is rather large, while that of the first j)remolar is 

 small. The second and third premolars are robust, and somewhat 

 swollen at the inner base. Each has a short heel but no median pos- 

 terior lobe. The principal lobe is robust, in the third molar as wide 

 as long at the base. The internal anterior lobe of the superior incisor 

 is very large, and its apex is distinct from the inner side of the rest of 

 the tooth. It is relatively larger than in the Crocuta hrumiea. The 

 anterior lobe is well developed, but does not project so far as the other 

 lobes. The first true molar is somewhat wider near the inner extremity 

 of the crown than at the external extremity. The two external tuber- 

 cles are not prominent nor well distinguished at the base from the 

 ledge-like external cingulum. The alveolus of the second molar indi- 

 cates a medium-sized tooth, and its anterior borders turned posteriorly 

 so that the long axis is directed as much backwards as inwards. En- 

 amel entirely smooth. 



The muzzle was of medium length. The malar bone has a prominent 

 acute postorbital process. The orbit was relatively as large as in the 



