_E. d. utahensis_: Wyoming: _Sweetwater Co._: W side Green River, 1 mi. N Utah Border, 1. Colorado: _Moffat Co._: Escalante Hills, 20 mi. SE Ladore, 1 (BS). Arizona: _Coconino Co._: Ryan, 1 (BS).
General tone of upper parts grayish; cheeks and underparts white, more or less dulled by gray; size large; skull large.
Baculum: Shaft thin; keel low, 2/5 of length of tip; tip 16 per cent of length of shaft; angle formed by tip and shaft 130°; distal 1/10 of shaft slightly compressed laterally; base incised dorsally; shaft markedly long, 4.88 mm.
Differs from _E. speciosus_, _E. panamintinus_, _E. umbrinus_, _E. palmeri_, and _E. bulleri_, in base incised dorsally, base not widened, shaft thinner, tip proportionally shorter; from _E. quadrivittatus_, _E. ruficaudus_, _E. cinereicollis_, and _E. quadrimaculatus_, in base incised dorsally, shaft thinner, tip proportionally much shorter.
For comparisons with _E. alpinus_, _E. minimus_, _E. townsendii_, _E. sonomae_, _E. amoenus_, and _E. dorsalis_, see the accounts of those species.
_Specimens examined_: One from Mount Piños, Ventura Co., California (LA).
Color bright and tawny; size medium to large; braincase widened.
Baculum of _E. q. quadrivittatus_: Shaft thick; keel proportionally low, 1/4 of length of tip; tip 30 to 44 per cent of length of shaft; angle formed by tip and shaft 130°; distal 1/3 of shaft slightly compressed laterally; shaft long, 3.17 to 3.62 mm.
Differs from _E. q. hopiensis_, in baculum larger, angle formed by tip and shaft less distinct; from _E. ruficaudus ruficaudus_, in shaft and tip proportionally shorter; from _E. r. simulans_, in keel proportionally lower, shaft usually shorter and narrower; from _E. cinereicollis_, in shaft shorter, angle formed by tip and shaft larger, ridges on either side of tip more distinct; from _E. quadrimaculatus_, in tip proportionally shorter, shaft shorter; from _E. speciosus_, _E. panamintinus_, _E. umbrinus_, _E. palmeri_, and _E. bulleri_, in base not markedly widened, shaft longer, angle formed by tip and shaft larger.
For comparisons with _E. alpinus_, _E. minimus_, _E. townsendii_, _E. sonomae_, _E. amoenus_, _E. dorsalis_, and _E. merriami_, see the accounts of those species.