797 
No. 175.| 
at this inclement reason of the year. It is of a lurid-yellow color, the 
legs and under side of its body paler, and its wrings of a slight smoky 
tinge expanding to the width of eighty-five hundredths of an inch when 
spread apart. It seems to differ in no very obvious particular from the 
Omithomyia avicularia of Europe. Whoever has observed one of 
these flies, will have been struck with the resemblance which exists 
between them and the well-known sheep-tick, except that they are fur¬ 
nished with wings. 
A larger species of these spider-flies, the Hippobosca Equi, of Lin- 
neus, is of a yellow color, with wings of a slightly russet tinge. It in¬ 
fests the horse ; but I am not aware that it has ever been discovered on 
this side of the Atlantic. 
Remarkable in this family, on account of its not possessing any 
wings, is the sheep-ticks, Melophagus Ovinus. It is less than a quarter 
of an inch long, and varies in the shade of its color, from rusty brown', 
to dull yellow, the hooks of its feet being black. Its body and legs are 
studded with short bristle-like hairs of a blackish color. In addition to 
its being wingless, another remarkable anomaly is presented to us in 
the history of this insect, as well as that of other members of this family. 
It does not undergo those several changes of form which take place in 
other insects. It has no larva or maggot state. It is a pupa, and not 
an egg that is deposited by the parent, and the perfectly formed insect 
comes directly from this pupa. It resembles a smooth, glossy seed, of 
a chesnut-brown color, and a regular oval form, slightly flattened, and 
is scarcely fifteen hundredths of an inch. At the head end, a slight de¬ 
pression is observable, in which are two punctured indentations. These 
pupse are always observed* scattered around in the fleece, when the 
sheep are being sheared. 
Ticks multiply on poor sheep, like lice on a sickly child or cow. 
They find a secure abode among the long dense wool of this animal, in 
which they ramble about with agility. They are always found in plenty at 
shearing-time. Many of them remain upon the fleece when it is carried 
to the store-room, and the shearer often finds one or more of them upon 
his clothes, or in his hair, sometimes several days afterwards, where, 
pressed by hunger, they in some instances attempt to pierce and ob¬ 
tain nourishment from his skin. Others remain upon the sheep after 
it is sheared, but by the removal of the fleece, their haunts are so broken 
up, that they forsake their old abode for the longer wool, which they 
now find upon the lambs. Hence, two or three days after shearing, the 
lambs will be found to be overrun with ticks, to their excessive annoy¬ 
ance, whilst the old sheep have became nearly or quite free from them. 
This affords the most convenient opportunity for destroy ing these parasites. 
