Topotypes of levis can be distinguished from those of Thomomys talpoides kaibabensis by markedly smaller measurements.

For comparisons with Thomomys talpoides parowanensis and wasatchensis see accounts of those forms.

Remarks.—Specimens from the Escalante Mountains and the Aquarius Plateau are not typical. They are of approximately the same color as levis, but are larger than levis and have cranial details that indicate intergradation with kaibabensis to the south. They resemble kaibabensis in large size, long nasals and widely spreading zygomatic arches, but are like levis in shape of the interparietal, extension of premaxillae posterior to the nasals, rounded posterior ends of nasals, ridged pterygoid hamulae and relatively short upper incisors. Additional material from these regions may prove these animals to merit separation and naming.

Specimens examined.—Total, 15, distributed as follows: Sevier County: Seven Mile Flat, 5 mi. N Fish Lake, Fish Lake Plateau, 10,000 ft., 2 (U. S. N. M.); Fish Lake Experiment Station, 2 (U. S. A. C). Garfield County: Posy Lake, Aquarius Plateau, 2 (B. Y. U.); 18 mi. N Escalante, 9,500 ft., 3; Steep Creek, Boulder-Teasdale Road, Boulder Mountain, 4 (B. Y. U.); Summit Birch Creek, Escalante Mountains, 2 (B. Y. U.).

Measurements of Adult Males of Thomomys

(In millimeters)

Total
length		Length
of tail		Length
of
hind
foot		Basilar
length		Length
of
nasals		Zygomatic
breadth		Mastoid
breadth		Interorbital
breadth		Alveolar
length
of
upper
molar
series		Extension
of
premax
post. to
nasals		Length
of
rostrum		Breadth
of
rostrum
T. t. gracilis, 4; topotypes
Av. 204 53 28 31.5 13.4 21.7 18.3 6.4 7.6 1.3 15.4 7.2
Min. 194 47 27 30.3 12.9 21.1 17.8 6.3 7.3 1.0 14.7 6.7
Max. 210 63 28 33.5 14.2 22.0 19.0 6.5 7.9 1.7 16.4 7.5
T. t. oquirrhensis, 4; topotypes
Av. 209 58 28 32.2 13.9 21.9 19.0 6.9 7.6 0.9 15.8 7.7
Min. 197 55 28 31.9 13.7 21.4 18.5 6.7 7.2 0.6 15.5 7.5
Max. 216 60 29 32.8 14.3 22.8 19.5 7.1 7.9 1.0 16.2 7.9
T. t. wasatchensis, 10; topotypes
Av. 221 67 28 31.3 13.4 21.5 18.9 6.5 7.4 1.1 15.1 7.4
Min. 204 60 26 27.4 11.6 19.1 17.2 6.0 6.6 0.9 14.0 6.7
Max. 237 75 31 34.5 15.2 23.7 20.4 7.3 8.0 2.0 16.5 8.2
T. t. uinta, 5; SW slope Bald Peak, Uinta Mts.
Av. 199 51 27 31.5 13.1 21.7 19.4 6.3 7.6 1.1 15.2 7.4
Min. 185 47 26 29.6 12.1 20.3 19.0 5.7 7.3 0.7 13.5 7.2
Max. 208 54 28 32.8 13.8 22.2 20.0 6.5 7.8 1.4 15.6 7.6
T. t. moorei, 7; topotypes
Av. 216 65 29 32.4 13.9 22.9 19.2 6.5 7.7 1.5 15.9 7.3
Min. 203 52 27 31.3 13.0 21.5 18.4 6.0 7.3 0.9 14.8 6.7
Max. 236 72 31 34.7 14.5 23.7 20.0 7.0 8.2 2.0 16.3 7.7
T. t. fossor, 8; Cascade Creek, La Plata Co., Colo.
Av. 215 61 29 31.7 13.2 21.2 18.7 5.9 7.5 0.6 15.5 7.1
Min. 202 54 27 30.5 12.0 20.5 18.2 5.5 7.0 0.0 14.5 6.9
Max. 228 70 30 33.0 14.4 23.5 19.9 6.3 7.9 1.1 16.9 7.4
T. t. ravus, 3; topotypes
Av. 248 73 30 35.2 14.6 24.8 21.4 6.3 8.3 2.4 17.1 8.2
Min. 244 70 29 34.5 14.3 23.6 20.5 6.0 8.2 2.2 16.7 8.1
Max. 253 74 30 35.9 15.1 25.7 22.5 6.7 8.4 2.7 17.5 8.5
No. 55270 (U. S. N. M.) T. t. pygmaeus, 1; topotype
165 40 20 24.6 10.2 16.3 15.1 5.4 5.9 0.7 12.0 5.7
No. 177506 (U. S. N. M.) T. t. ocius, 1; 12 mi. W Linwood, Henrys Fork, Wyo.
200 62 26 27.5 11.5 19.9 17.8 6.2 6.8 1.0 13.5 7.0
T. t. parowanensis, 2; Britts Meadow, Beaver Mountains
Av. 215 59 28 34.3 14.5 22.4 18.6 6.0 8.1 1.4 17.3 7.9
Min. 202 48 27 34.1 14.1 22.0 18.4 5.8 8.0 1.0 17.2 7.6
Max. 228 69 29 34.6 14.8 22.7 18.9 6.2 8.2 1.7 17.3 8.2