MURID ®&—SIGMODONTES—OCHETODON LONGICAUDA. 12 
Haprrat.—California (Samuels, Stimpson, Xantus). ? Guatemala ( Tomes). 
“Size small. Tail considerably longer than the head and body (which 
measure from 2.10 to 2.30 inches), usually from 8 to 8 tenths of an inch 
longer. Hind foot .65 to .70 of an inch. Above, dark brown: beneath, 
white, tinged with reddish yellow. A broad wash of bright fulvous on the 
sides and cheeks.”—( Baird, 1. c.) 
This animal, accurately indicated by Baird as above, is certainly dis- 
tinguishable from O. humidis, though the full question of its specifie difference 
from humilis is perplexing. While we have never seen an Atlantic Ochetodon 
with the tail-even as long as the body, and while even in the Middle Region 
the tail never exceeds the trunk, there is no example of dongicauda in which 
this member is not notably longer. The trunk ranges, as shéwn by the fol- 
lowing table (mostly copied from Baird’s published ona), from 1.83 to 2.40, 
settling near 2.25 as an average, while the tail ranges from 2.25 to 3.15, only 
once, however, touching this last figure, and usually falling under 3.00. The 
feet, likewise, are somewhat larger, ranging from 0.60 to 0.70, with an aver- 
age of 0.66, only once reaching 0.70, and. perfectly connected with those 
of humilis by intermediate measurements ; though in humilis the feet rarely 
reach 0.66, and will not average over 0.60. The colors of dongicauda are 
likewise noticeably different; only a restricted dorsal area is as dark as in 
ordinary humelis, while the whole sides of the head and body are broadly and 
brightly fulvous, and the under parts are washed with the same. This lively 
shade is not even approximately attained in any* specimen we have seen 
except 9339 from Iowa. 
We have, therefore, little hesitation in indorsing the name, though certain 
facts arouse our suspicion and prevent us from making out a perfectly satis- 
factory case. Thus, Audubon and Bachman have described a Carolina animal 
nearly identical with /ongicauda in proportions. Then, again, in our speci- 
mens from intermediate localities, as Missouri, Iowa, and Nebraska, the tail 
lengthens to an equality with the body, and the feet average over 0.60. The 
question is resumed and more fully stated under head of the next species, 
mexicanus. We cite the above Guatemalan reference with a query, suspect- 
ing that this particular form does not occur in that locality; but, of course, 
we have no assurance that such is not the case. 
