COPE.] PALEONTOLOGY MIOCENE PEEIOD. 497 



is over the front of the fourth premolar 5 it is above the front of the 

 third in A. hairdii. 



Measurements. 



Lengtli of fourtli aud fifth molars 0.0275 



Length of fourth molar 0140 



Width of fourth molar 0125 



Elevation of fourth molar .0080 



Length from front of malar to foramen ivfraorhitale anterius 0140 



This species diifers from the A. agreste, Leidy, in size about as the A. 

 dairdii. The former is only known from mandibular teeth. 



Anchitheeium cuneatum. Cope, Paleout. Bull., No. IG, p. 7, (August 

 * 20, 1873,) specimen jSTo. 1. 



The smallest species of the genus represented by both maxillary 

 bones of one individual ; several loose molars and a maxillary bone 

 with teeth of others. In the first-named specimen, the second premolar 

 has the elongate form of the corresponding deciduous molar of A. 

 hairdii, but I am not sure whether it is the deciduous or permanent one 

 in the present case, as the series only includes the fifth molar. The 

 middle anterior tubercle is directed forward, inclosing an angular fossa 

 with the inner. The latter is separated from the posterior by a basal 

 tubercle, but there is none on the third premolar. The posterior median 

 tubercle is well developed. The outer faces of the outer lobes are con- 

 cave ; sometimes with a faint median ridge. 



The fore and aft cingula are well developed, and the basal parts of 

 the posterior transverse ridges are connected with the posterior median 

 tubercks. 



2Ieasurements. 



M. 



Lengthof M. 2and3ofNo. 1 0.0260 



Length of M. 1 of No. 1 0130 



Width of M. 1 of No. 1 0110 



The specimen measured as 'No. 2 in the original description does not 

 belong to the species. 



Another specimen contains what are without doubt the permanent 

 third, fourth, and fifth molars. These resemble the corresponding 

 ones of the specimen just described, differing only in being a little 

 smaller. Besides the small size, they differ from those of A. hairdii in 

 the entire absence of the inner basal tubercles, and in the rapid reduc- 

 tion in size of the molars from the fifth forwards. The anterior median 

 lobe is very distinct, and the posterior median small. 



Measurements. 



M. 



Length of third, fourth, and fifth molars 0.0350 



Length of third molar Oil 



Width of third molar Oil 



Width of fifth molar 014 



Length of fifth molar .013 



Since the description of this species was published. Professor Marsh 

 has described an AncJiitherium of about the same size, from the Miocene 

 of Nebraska, under the name of A. celer.* It will be desirable to 

 institute comparisons between these to settle the question of their dis- 

 tinctness or identity. 



32 G s 



Amer. Journ. Sci. Arts, 1874, p. 251. 



