ARTIODACTYLA 
347 
some of tlie specimens the horns are continuous with the frontal bones, as 
in the Antelopes, etc., while in others the basal part of the beam is furnished 
with protuberances in the form of a burr. These observations have also 
been made on the American species by myself, and published in the Report 
on the Vertebrate Fossils obtained in New Mexico (see Annual Report 
Chief of Engineers, 1874, p. 604). The specimens obtained by the expe¬ 
dition prove that four, perhaps six, species of this genus occur in the Santa 
marls, one of which had been previously found by myself in the Loup 
Fork beds of Colorado and two others in the con-esponding formations in 
Nebraska by Dr. Hayden. To one of the latter the name of Merycodus 
necatiis was applied by Dr. Leidy in 1854, and Cervus ivarrenii in 1858. 
The former was represented by mandibles with dentition; the latter by 
horns. The discovery of crania with horns and teeth, enables me to unite 
these supposed species. A third species, discovered by Dr. Hayden in 
Nebraska, was named by Dr. Leidy Cosoryx furcatus in 1869. In com¬ 
menting on this species. Professor Gervais remarks (Journal de Zoologie) 
that the genus Cosoryx is not distinct from Bicrocerm, a statement confirmed 
by the comparison with the figures of the B. dicJiotofnus, Gerv., from the 
French Miocene. 
More or less fragmentary horns of nineteen individuals of this genus 
were obtained by the expedition, of which thirteen, representing three 
species, include the basal part of the beam. As already remarked, some 
of these present a basal burr and some do not. Those in which the beam 
is without burr, or scar of it, are, B. 'teres^ 1; D. necatus, 5; B. furcatus, 1. 
Those with the burr or scar are, B. necatus, 2; B. furcatus, 4. The occurrence 
of both these conditions in the same species indicates that the character, so 
constant and important in the definition of the existing Buminantia, is here 
subject to causes the discovery of which will add an important item to the 
history of the origin of the genera, families, etc., of this order. A considera¬ 
tion of some other parts of the specimens throws additional light on the 
question. 
In a specimen of each of the species B. furcatus and B. necatus, an 
antler is broken off, and just below the fractured extremity a burr or ring 
of osseous tubercles has been thrown out. The free extremity is short, and 
