70 
LINNEAN SYSTEM. 
Genus 69. Mutilla. 
MoUth, horny, without a tongue : maxilla membranaceous at the apex, 
the lip projecting, obconical, bearing on its apex four unequal palpi 
with obconical articulations : antenna filiform . In general the males 
are winged, and tire females arc apterous: body pubescent : sting 
concealed. 
Sp. 1. Mutilla europaa, (PI, 8. Jig- 11. male.) 
Order VI. DIPTERA. 
This Order includes all those insects that have but two wings, and 
behind, or below them, two globular bodies, supported on slender pc- 
dicles called Ha/teres orpoisers. At the mouth they have a proboscis, 
sometimes contained in a vagina, and sometimes furnished at its sides 
with two palpi but no maxilla. Their eyes are reticulated and large. 
The females, in general, lay eggs, but some are viviparous; the larvs 
of the insects of this order are as various in their appearance as the 
places in which they are bred. In general they do not cast their skins, 
but change into a pupa state. 
Genus 70. Oestrus, Gact-fly, 
Haustellum retracted within the lips, which are tumid and grown to- 
gether with a small pore and no palpi ; the vagina is membranaceous, 
cylindrical, obtuse, including three membranaceous seta, which are 
flexible, short, and reflected; antenna short and setaceous. 
The insects of this genus lay their eggs in the nostrils or in the skins 
of horses, oxen, rein-deer, goats, and sheep; their larva is bred, and 
feeds on the fat of these animals, or on the matter which is generated 
in the wound. It is soft and without feet : in some species it has at the 
extremity two hooks, which it uses to assist it in walking. These hooks 
are wanting iri die larva: which reside in the skins of oxen and rein- 
deer. When full grown the larva’ let themselves fall on the ground, 
they enter the earth and change into an oval hard pupa. The perfect 
insect takes no food. [Mr. Bracy Clark has written an excellent paper 
on the insects of this genus, published in the third volume of the 
Transactions of the I.innean Society; which has been rc-published with 
additional remarks, and entitled an Essay on the Bots of Horses, Sec. 
4to, 1815.] 
Sp. 1. 0. Bvvis. (PI. 9. fig. 1.) 
Genus 71. Tipula. 
Month furnished with a very short proboscis, membranaceous, grooved 
on the back, and receiving a bristle ; a short haustellum without a 
vagina; two incurved palpi, equal, filiform, and longer than the headj 
antenna in most species filiform, 
