480 
ANNUAL REPORT OF NEW-YORJT 
SUPPLEMENT. 
with two grubs in its scrotum, considerably torn and injured by 
the coarse shot with which it was killed. These grubs are plainly 
the larva of a bot-fly and not of a flesh-fly. They are placed 
lengthwise in the scrotum, one forward of the other, producing a 
tumor nearly an inch and a half in length. Each worm has a 
cavity for itself, separated from the other, with an orifice towards 
its hind part, larger than the head of a large pin. Though the 
worms are probably immature the testicles appear to be entirely 
consumed, but the parts are so torn that I do not attempt to trace 
out the exact lesion which they have produced. 
Of these two larva: that which is least injured is 0.65 long and 0.44 broad. 
The other is smaller, being only 0.32 broad. They, are oval, moderately 
depressed, more flattened beneath than above, rounded at one end and some¬ 
what pointed at the other, of a coal black color and shining, the whole outer 
surface being covered with slightly elevated small hard angular granules, like 
shagreen, but without any projecting spines or teeth-like processes. The skin 
is remarkably thick and tough like leather, and the rough angular points with 
which it is covered must produce much irritation in the tumor, especially when 
the worm moves. It is divided into ten segments by deeply impressed trans¬ 
verse furrows, each segment forming a prominent ridge which is most elevated 
towards its hind edge. Towards the outer side each ridge is cut across by a 
conspicuously impressed longitudinal line, giving the worm a thrce-lobed 
appearance similar to that of a trilobito fossil. On the under side is an analo¬ 
gous impressed line, and between these at equal distances along each side arc 
two others less deeply indented. The mouth does not show any jaws or other 
appendages externally but appears like a simple elliptic orifice placed trans¬ 
versely; and the perforation at the opposite end is similar. The specimens, 
however, are so mutilated that they do not afford a satisfactory examination. 
The worm is much like the figure in Westwood above referred to. 
July 29th, 1857. I have repeatedly raised the tumbler to see 
if the worm buried last August bad hatched, and began to des¬ 
pair of obtaining anything from it, when to-day, to my great joy, 
I find a large flv lying upon its back, dead, upon the surface oi 
the dirt in the tin box, with the ends of its wings worn off from 
flying in its narrow prison, but perfect in every other respect. It 
proves to be of the bot-fly family (( Estridce ) and of the genus 
Cuterebra of Clark, thus named from two Latin words, cutis tere- 
bra, i. e. skin borer or skin piercer, this genus being distinguished 
by having the bristle of the antennfc feather-like or ciliated with 
a row of fine hairs along each side, and showing a distinct orifice 
