214 MUS, MUSCA. 
americanus, (american rat,) tail long, scaly ; head 
long 3 nose pointed ; upper jaw longest ; ears 
large, naked. About 8 inches long, or smaller. 
musculus, (house-mouse,) tail long, nakedish ; fore- 
feet four-toed, hind feet five-toed, thumb with- 
outaclaw. + inches long. 
sylvaticus, (field-mouse,) tail long, scaly ; body 
yellowish-brown, white Beneath, ‘braie yellow- 
ish. Var. albus, entirely white. 
* messorius, (harvest mouse,) tail long, scaly ; body 
rusty-brown, belly white, colours divided by 
a straight line. 
virgimianus, (pasture mouse,) tail all hairy, thick 
at the base, long, tapering ; body whitish or 
white, nose biack. 
amphibius, (water rat,) tail middle length ; ears 
hardly above the fur ; feet three- toed, with the 
appearance of a fourth. Sometimes hind feet 
five-toed, Dark or blackish. Body 7 inches 
long, tail three. 
ae Ms. P. 
8—12. Musca. Spec. about 530. 
domestica, (house-fly,) with two short feelers. 
sucker with a ile bristle without skéath . 
hairy, black; thorax with five pale lines ; ab- 
domen tessilate, pale at the base beneath. 
cadaverina, (carrion eater,) body polished ; thorax 
blue; abdomen green. FKeelers and suckers 
like domestica. 
mortuorum, (death fly, epidemic fly,) thorax black ; 
abdomen green bronze; legs black ; thorax 
with a few faint lines. Feelers and suckers 
like domestica. 
