1881.] -^-^^ [Cope. 



Triisodon heilprinianus, sp. nov. 



This species may be readily recognized as smaller than the T. quimren- 

 sis, and as having the anterior inner cusp of the inferior true molar of 

 larger proportions than in the corresponding teeth of the latter species. 

 It is only represented in my collection by a portion of a lower jaw, which 

 supports only one well preserved molar. As the fourth premolar is not 

 present, it is not positively ascertained that the species does not belong to 

 Ictops. 



The anterior cusp is very low, and is nearer the inside than the middle 

 of the anterior border. The principal anterior cusps are opposite, and the 

 external is a little the larger. The heel is larger than the basis of the an- 

 terior cusps, and has convex borders. Its internal border supports three 

 tubercles, and the external border rises into a cutting lobe with lenticular 

 section. Enamel smooth. No cingula, but the external base is injured. 

 Measurements. M. 



. (of cusps 0070 



^. , ,. , . , ^e^t'^^M of heel 0053 



Diameters of mferior molar \ . ^ . . . 



anteroposterior 0110 



^- transverse 0065 



Puerco beds of New Mexico. 



Dedicated to my friend, Professer Angelo Heilprin, of Philadelphia. 



Sarcothraustes antiquus, gen. et sp. nov. 



Char. gen. We have in evidence of the characters of this genus, the 

 last two supei'ior molars, the last one lacking the crown ; and parts of 

 both mandibular rami, which exhibit teeth as far posteriorly as the first 

 true molar inclusive ; all belonging to one individual. A part of a skele- 

 ton of a second individual, which includes a fragment of lower jaw, be- 

 longs probably to this species. 



Sarcothraustes resembles both Amhlyctonus and Mesonyx, but it is prob- 

 ably to the latter genus that it is allied. The last superior molar is trans- 

 verse, much as in Oxycena. The crown of the penultimate is subtriangular 

 and transverse. It has two external subconic cusps and a single internal 

 lobe, whose section on wearing is a V, each branch of the face extending 

 to the base of the corresponding external tubercle. There are three small 

 inferior incisors, and a large canine. There are probably only three in- 

 ferior premolars, the first one-rooted. The crown of the second has no 

 heel. The crown of the third has a short wide heel. The crown of the 

 first true molar consists of an anterior elevated cone and a posterior heel. 

 The latter is wide, having a posterior transverse, as well as a longitudinal 

 median keel. The fragments of the supposed second individual include 

 two large glenoid cavities with strong preglenoid crests, as in Mesonyx. 



As compared with Mesonyx, this genus differs in the V-shaped crest of 

 the penultimate superior molar ; in Mesonyx it is represented by a simple 

 cone. The last superior molar of Mesonyx is triangular and not transverse, 

 but the composition of the crown of that tooth in SarcotJiraiistes must be 



