1877. ] 223 
[Cope. 
tainly distinct from Dicrocerus Lartet. The discovery of a second species 
of the group, which displays the characters there pointed out, in a still 
more striking degree than the species on which it was formed, renders it 
necessary to introduce the genus formally to the system. In brief its 
molars differ from those of Dicrocerus much as those of the deer differ from 
the molars of the antelope. While Dicrocerus was probably the ancestor 
of Antilocapra, Blastomeryx was the ancestor of Cervus or Cariacus. 
The superior dental formula is I. 0; C.0; Pm. 3; M. 8. The molars 
all have two pairs of crescents excepting the last premolar, where the pos- 
terior pair are rudimental. The external face of the anterior crescent in 
all the molars presents a groove, which is bounded posteriorly by a vertical 
ridge. The posterior crescent is directed a little inward posteriorly on the 
true molars. The palate is much contracted in front of the first molars. 
The horns stand above the posterior parts of the orbits; their section is 
triangular, the posterior angle being rounded, and the external produced 
and acute, bounding the orbit outwards and backwards. There is no trace 
of burr. The temporal fossze approach so as to be separated only by a 
rather wide and low occipital crest. 
Measurements. M. 
MOEN een Ce Waillles. soso coon docmucgecos mob Enonomp 820 
i Spa OVE TNOVE WE URSIB IES 32.85 Bo Goin adm otes Sano eOooGs 107 
as TOLEUINO] Aieeut rere vate et qavercreie) aioe) Perstoisione st etore ors .049 
a SeCOMMs premolar sachiels oe selects eects .016 
Width cs OSM ARONA Scertalery. china sate he tolieistaretenanys O11 
Beneth of rst true wiaiar patie t's cae <ieins oa eleicls dain J elas, 020 
Width uf GOMES 2 F ateta och eteishelers Mae ates Ob .015 
Width between bases of horn-cores............ See a sheial sve .050 
Transverse diameter of horn-core two inches from base. . .040 
Width between external borders of first true molars..... 078 
Width of palate in front of first premolars.............. .028 
This species was as large as the black-tailed deer, Cariacus macrotis. Tt 
was found by my assistant, J. C. Isaac, in the Upper Miocene of Montana. 
CERVUS FORTIS sp. nov. 
This deer is of large size, much exceeding any living species of the 
family Cervide. It is represented in my collections by a superior molar 
of the left side, and very probably by other remains which accompanied it, 
viz.: a mandibular symphysis with incisor and canine teeth; calcaneum. 
astragalus, vertebra, etc. These were found at the same time and place 
by George M. Sternberg, M.D., U. 8. A., already well-known by his in- 
teresting discoveries in the cretaceous formation of Kansas. 
The plice which mark the anterior extremities of the external crescents 
are very prominent, and are directed forwards rather than outwards. The 
median lakes are narrow and well separated medially. The posterior lake 
has a strong fold of its internal border, forming a lobe directed backwards. 
