1880. | Geology and Paleontology. 747 
cusps. The V-shaped crests of the inferior molars separate it 
from Hyracotherium. Char. specif. The heels of the second and 
third premolars have a median keel; the third only has an ante- 
rior tubercle. The crest of the heel of the fourth forms an im- 
perfect V. Heel of the last true molar small. No. cingula; 
enamel smooth. Length of molar series .o80; of true molars 
044; of last molar .o1g; depth of ramus at first premolar .021; 
at last molar .031. Second specimen. Diameters of crown of last 
Superior molar: anteroposterior .014; transverse .o16. About 
the size of the Hyrachyus agrestis. Three individuals. 
(14) Hyracotherium angustidens Cope, jaws of three specimens. 
(13) Hyracotherium vasacciense Cope, one jaw. (16) Hyraco- 
therium vortmant sp. nov. About the size of the H. tapirinum 
Cope, but. with the opposite cones of the inferior molars not 
united by cross-crests. There is a tubercle between the posterior 
pair of the first inferior true molar. The anterior tubercles of the 
fourth premolar are close together, and there is a strong cusp 
anterior to these. No basal cingulum on this tooth. Length of 
molars 3 + 4 + 5, .025; depth of ramus at p. m. Iv .o18. 
(17) Hyracotherium craspedotum sp. nov. Size of H. tapirinum, 
but the tubercles of the inferior molars are not connecte 
Cross crests, and they all possess a strong external basal cingu- 
lum, which also extends round on the posterior base of the land II 
true molars. Heel of fourth premolar with a diagonal ridge; 
them. Second premolar with narrow heel; last true premolar 
with wide heel. Length of molar series .056; of true molars 
033; of last molar .014 ; depth of ramus at second premolar; .o18 
at last true molar .o 
with wide heels, each with a single low ridge. ngth of molar 
Superior molar at No. 2: anteroposterior .012 , transverse .O1 
(19) Lophiodon ventorum sp. nov. Larger than the last, and 
differ ing in having a large heel of the last true molar, and an 
om the preceding it appears that this fauna, though | in 
general that of the Wasatch Eocene, present certain peculiarities, 
