along the Rio Grande, _consitus_ differs in: Body smaller; tail and
hind foot shorter; upper parts paler, more buffy and less rufous;
skull markedly smaller, especially in palate and nasals; zygomata less
widely flaring; tympanic bullae more inflated; mastoid bullae less
inflated; basioccipital parallel-sided as opposed to wedge-shaped.
From _Cratogeomys castanops convexus_, found to the east, _consitus_
differs in: Body smaller; tail and hind foot shorter; upper parts
paler, more buffy and less ochraceous; underparts paler, white or
light buffy instead of pale ochraceous; skull smaller; zygomata less
widely flaring; palate shorter; rostrum decidedly narrower and,
relative to length of skull, longer; squamosal breadth less; incisors
smaller. From _Cratogeomys castanops excelsus_, found to the south,
_consitus_ differs in: Size smaller; tail and hind foot shorter; upper
parts darker, more rufous and less pinkish-buff; skull conspicuously
smaller, especially in palate, rostrum, and nasals; zygomata less
widely flaring; mastoid bullae and tympanic bullae more inflated;
incisors smaller; maxillary teeth relatively larger. For comparison of
_consitus_ with _Cratogeomys castanops sordidulus_, see previous
account.

_Remarks._--_Cratogeomys castanops consitus_ is a small pocket gopher
(see tables 1 and 2); the largest adult available to us is much
smaller than the smallest adult of any adjacent subspecies. Specimens
from Coahuila assigned to _consitus_ compare favorably with
topotypes although those from the vicinity of Jaco are smaller, paler
and have a narrower rostrum and smaller maxillary teeth. An immature
male trapped three miles northeast of Sierra Mojada is tentatively
assigned to _consitus_. This subspecies seems to be rare in
northwestern Coahuila and small colonies are widely scattered.

_Cratogeomys castanops clarkii_ (Baird) may occur along the Rio
Grande in extreme northwestern Coahuila. No specimens are known from
Coahuila, and none was found in the vicinity of Boquillas, Coahuila,
in 1952.

_Specimens examined._--Total, 8, from: 3 mi. N and 9 mi. E El Pino, 1;
6 mi. E Jaco, Chihuahua, _in_ Coahuila, 6; 3 mi. NE Sierra Mojada, 1.

+Cratogeomys castanops excelsus+ Nelson and Goldman

1934. _Cratogeomys castanops excelsus_ Nelson and Goldman, Proc. Biol.
Soc. Washington, 47:143, June 13, type from San Pedro, 10 mi. W Laguna
de Mayran, Coahuila.

_Distribution._--Desert plains of southwestern Coahu