98 Bulletin American Museum of Natural History. [Vol. XXXIV, 
Measurements. 
Type, No. 72 No. 2959 No. 15227 No. 15226 
P!, diameters a.—p. X tr. 
¢ 
P2 ‘ 18.4 X 15.4 
P3 a 28 ATS 
Pe pee 22.8 X 23.5 24.4 X 24.6 
- Mt = 26.0 X 25.8 2554: 3% 241 
M? . 26.45% BOs]. 20co 20.0 Oe yc ee 
M3 ie 25.9 x 25.4. -22.0 27.8 
Dp! ce oO 20 6 
Ci es : 30.8 xX 21:8 
P; rs Mt OC Tt 
P3; a 95.0 15.1 25.6% 14.3 
Pj o 28.9 X 16.4 
Mi 3, OS io 18.8. obo «17.8 
M, u 32.2 AGS Stes 18 4 
M; - 30,0 13.9 
Da gee O22 AGT 
Dps bs : 13.3 << 8.9 
Dps os 73-9 << 11.0 
Astragalus, diameters 57.0 X 56.4 
i width of trochlea 32.8 
Pachyena gigantea ponderosa subsp. nov. 
Type, No. 15228, upper jaw, lower teeth, astragalus and lunare, from Gray Bull 
beds of Big Horn Basin. 
We foi2 2B: A, i. 
Fig. 85. Pachyena gigantea ponderosa. Upper teeth of type specimen, two-thirds 
natural size. Gray Bull beds, Big Horn Basin. 
Distinctive characters: M'-3 = 85 mm. M!-? larger, m? smaller than in gigantea. 
Astragalus one tenth broader. 
Although closely allied to P. gigantea, the larger size of the teeth and 
greater reduction of m* constitute a marked approach to Harpagolestes, and 
