CREODONTA. 
117 
Stypolophus strenuus, Cope. 
Plate xxxix, fig. 11. 
Prototomus strenuus, Cope, System. Cat. Vert. Eocene New Mexico, U. S. Geog. Survs. 
W. of 100th M., 1875, p. 10. 
Both mandibular rami, with representatives of all the teeth except the 
first premolar, form the basis of our knowledge of this Creodont. The 
characteristic feature is the great robustness of the jaw, as compared with 
the species last described, as well as the somewhat larger size. The third 
premolar has a cutting-edge and basal tubercle in front, which are wanting 
in the 8. multicuspis. The third and fourth premolars are stout teeth, com¬ 
posed of a large cusp of lenticular section, and a trenchant heel. The 
fourth is thickened on the inner side, but the apex cannot be described, as 
it is broken away. The penultimate molar is larger than the last one, and 
its heel, like that of the preceding tooth, is well developed. The first true 
molar is smaller than the second, and its cuspidate portion smaller than the 
corresponding parts of the last molar. The inferior canine is stout at the 
base and acute at the apex. The external face exhibits two shallow longi¬ 
tudinal grooves, separated by a low convex rib. Enamel of all the teeth 
smooth. 
Length of the last five molars...... 0. 0375 
Length of the last premolar.*. 0. 0080 
Length of the first true molar...;. 0. 0080 
Length of the second true molar. 0. 0080 
Width of the same... 0. 0065 
Length of the last true molar.. 0. 0075 
Depth of the jaw at the last true molar..... 0.0210 
Depth of the jaw at the second premolar. 0. 0175 
Thickness of the jaw at the same..... 0. 0080 
Length of the inferior canine .. . . 0. 0123 
Long diameter of the same at the base. .... 0. 0065 
The thickness of the mandibular bones is twice as great as that of the 
species last described. 
Other species formerly referred to this genus were subsequently placed 
in Aplieliscus and Pelycodus resjDectively. 
