318 Bulletin American Museum of Natural History. [Vol. XXXIV, 
on m*, deuterocone of p* more triangular than in H. miticulus with weaker 
cingula on its anterior and posterior faces. : 
Referred specimens in Amer. Mus. Coll., Nos. 16081, anterior half of 
skull, 16082-7 upper and lower jaw fragments. All from Sand Coulée 
beds of Clark Fork basin. Length, m;-3 = 10-11 mm. 
This species shows a marked approach to Haplomylus, and through that 
genus to the Miocleenide and the smaller Periptychide. 
Hyopsodus miticulus (Cope 1874). 
EKsthonyx miticulus Corr, 1874, Rep. Vert. Foss. New Mex., p. 8; (Hyopsodus) 
1875, Syst. Cat. Hoc: Vert. New Mex., p. 8; 1877, Rep. Vert. Foss. New Mex., p. 
150, pl. xlv, figs. 10-12.— Ossorn, 1902, Bull. A. M. N. H., Vol. XVI, p. 183, fig. 6. 
Type, a lower jaw 
fragment with mj-3, fig. 
10 of Cope’s 1877 re- 
port. Not found in 
National Museum col- 
lection.) 5: 
AY Pd. | : The species is dis- 
tinguished by small 
size, short wide molars, 
short and small fourth 
premolar. | Hypocone 
strong on m?? but 
smaller than protocone; 
a small hypocone on m‘°. 
M? smaller than m!, 
metacone usually small. 
Deuterocones of p** 
relatively small. En- 
toconid imperfectly 
separated from hypo- 
conulid. Length of 
Fig. 4. Hyopsodus miticulus, topotype, upper and lower Hh-3>= 10.5 to 12 mm. 
jaws, No. 16199. Cro i : 
sie | wn views of upper and lower teeth No. 16199, upper 
pt+-m3, pa—-ms3 and external view of lower jaw, all enlarged to : , 
three diameters. Almagre beds, Arroyo Blanco, Wasatch and lower JaWS from 
of New Mexico. the Almagre horizon of 
: New Mexican Wasatch, 
agrees with Cope’s figure and description and may serve as topotype. No 
additional specimens from this region, but it is very abundant in the Gray 
