76 DIPTERA. 



very small, with rudimentary oral organs. The mid- 

 dle part of the face is exceedingly narrow, and the 

 minute antennae are inserted in rounded pits." Pack- 

 ard I, 403. 



The Horse Bot-fly, Gastrophilus equi Fabr. — Eggs . 

 attached to the hairs on legs and shoulders of horses. 

 LarvK licked off by the animal's tongue and swallowed 

 with the food. They fasten themselves to the walls 

 of the stomach, and remain there until full grown. 

 They then pass from the animal with the excrement, 

 and undergo their transformation in the dried skin of 

 the larva. (13, 1869, p. 96). 



Bot-fly of the Ox, Hyphodcrma hovis DeGeer. — Eggs 

 deposited on backs of Cattle, Larva; pierce the skin 

 and live under it in tumors produced by their irritation. 

 When full grown they leave the tumors and fall to the 

 ground, where they transform within the dried skin of 

 the larva. (13, 1869). 



The Sheep Bot-fly, QLstrus ovis Linn. — Eggs or 

 young larva; deposited in the nostrils of sheep. Larvae 

 live in the frontal sinuses, where they feed upon the 

 mucous. They are verv injurious to the sheep, caus- 

 ing vertigo or " staggers." Pupa state passed beneath 

 the surface of the ground, in the dried skin of the 

 larva. (3, I, 161). 



MUSCID/E. 



The following species will serve as illustrations of 

 the form and habits of the members of this very large 

 family. 



The House-fly, Miisca domestica Linn.* — Eggs, 



*See paper by Packard, on the transformations of the common House-fly, from the 

 Proceedings of the Roston Society of Natural Historj-. Vol. XVI, Feb. 1874. 



