club shaped organs well beset with bristly hairs ; these are the palpi or feelers which some naturalists 
indeed believe to be more than mere feelers, organs perhaps of smell, taste, or even of both. 
No. 4. Represents the proboscis of the Blow-fly {3fusca votnitoria) magnified 42 diameters. Negative 
No. 536, new series. Considerable difference will be observed in the size and form of the sucking lobes, 
the number and shape of the false tracheae, the shape of the palpi, &c., but the general structure is quite 
similar to that of the proboscis of the Wine-cellar Fly. 
No. 5. Exhibits the fleshy lobes of the same proboscis magnified 80 diameters. Negative No. 540, 
new series. In this picture the false trachea? and their circular rings, the central cleft between the two 
lobes and the triangular oral orifice, are well seen. The sucking tube of the second joint being dark-yellow 
in the preparation appears as a black streak in the picture. The size and arrangement of the bristles 
which beset the second joint and fringe the sucking lobes are worthy of notice. 
No. 6. Represents the proboscis of the common House-fly ( Musca dome&tica) magnified 85 diameters. 
Negative No. 541, new series. The parts are essentially the same as those of the Blow-fly though smaller 
and somewhat modified in form. In the preparation copied, the second joint of the proboscis has been 
broken and a part of its outer membrane turned to the left. 
No. 7. Represents the proboscis of the Zone-fly ( YoluceUa zonarid ) magnified 40 diameters. Nega- 
tive No. 450, new series. This fly, in size and general appearances, resembles the llumblu-bee. Availing 
herself of this circumstance the female fly enters the nests of the bees and lays her eggs, to hatch out 
voracious larva? which prey upon the larva? of the bee. The photograph is added chiefly because it exhibits 
the fleshy lobes of the proboscis, which is similar to those already described, in a partially collapsed con- 
dition. In the lower part of the picture, on the right hand side, may be seen a combination of lancets, 
produced by special developments of the maxilla?, mandibles, and tongue, (Lownes, loc. cit. p. 45.) which 
do not correspond to anything shown in the other pictures, and which therefore need no special comments 
in this place. 
I have the honor to be, General, 
Very respectfully, 
Your obedient servant, 
.1. J. WOODWARD, 
Assistant Sure/ can, U. S. Army. 
