214 
The Mammals of Colorado 
North and South Carohna, Georgia, Kentucky, Tennessee, 
eastern Florida, Alabama, Mississippi, Louisiana, Texas, 
Oklahoma, Kansas, Nebraska, Iowa, South Dakota, Colo- 
rado, Utah, New Mexico, Arizona, Nevada, Idaho, Washing- 
ton, Oregon, and California, and the genus is also found in 
Lower California, and southward through Mexico as far as 
Guatemala. 
Key of the Species 
A. Tail without white tip. S. interrupta, p. 214 
B. Tail with white tip. 
a. Skull and brain-case broad and flat; auditory bullae and 
mastoid capsules well inflated, rather prominent from 
above and behind, 
a'. Zygomata widely and abruptly expanded, highly arched 
upward. S. arizonae, p. 216 
b'. Zygomata not so widely expanded, and not so highly 
arched. S. tenuis, p. 216 
b. Skull and brain-case flat as above, but the lambdoidal ridge 
is lower, so that when the skull is viewed from behind 
much more of the upper part of the brain -case is seen; 
auditory bullae and mastoid capsules not so inflated as to 
be noticeable from above. S. gracilis saxatilis, p. 217 
Spilogale interrupta (Lat. breaking apart, interrupted, 
referring to the markings). Prairie Spotted Skunk. 
Mephitis interrupta Rafinesque, Annals of Nature, i., p. 3 (1820). 
Type locality. — "Upper Missouri" River. 
Measurements. — (Of specimen described below) : Total length, 
19. 1 ; tail vert., 7.85; hind foot, 2.05. 
Description. — (From a specimen taken at Wray, Yuma County, 
March 5th) : White markings as described for genus, but the 
stripes are all narrow, the dorsal ones especially so; spots rather 
small; tail full and bushy, and just a very few white hairs in tip, but 
it is not conspicuously white-tipped. Skull rather small and 
slender, brain-case arched ; auditory bullae and mastoid capsules 
only moderately inflated. 
The full bushy tail, with little or no white at tip, at once dis- 
tinguishes interrupta from the other three species of Spilogale found 
in Colorado. In general the extent of the white marking is much 
more restricted than in the other three species. 
Distribution. — The Prairie Spotted Skunk is found in Iowa, 
