126 HORSE AND GATTLE FLIES. 
and the hinder part is also terminated in a cone, but much shorter 
than that of the fore part, It is divided into twelve rings, of which 
the terminal ring is nipple-shaped. 
“The colour of the larva is of a dirty yellowish white, . . . with 
seven roughish or somewhat raised bands of a blackish colour placed 
on the fore part of the fourth, fifth, and following segments to the 
tenth inclusive, and which encircle the body like hoops. These same 
segments have towards the sides and at the lower part some fleshy 
tubercle-like projections, which the larva can withdraw into the body 
or push out again at pleasure.” [By the help of this contraction and 
expansion, and the use of the head-hooks at the same time, the footless 
larva carries on its somewhat worm-like progression.—H. A. O.] 
‘‘ The little head is brown and shining, of a lengthened shape, and 
has two small short antenne, and two large hard hooks of the length 
of the head placed above, but curved downwards. . . . When at rest 
it withdraws the head into the first segment, and this into the second, 
and then the fore part of the body is as thick as the rest. 
“The nymph’ [pupa] ‘of this larva is nearly an inch long”’ [see 
figure, p. 123], ‘‘and of the same thickness as the maggot, and of 
almost equal thickness throughout, excepting the last ring of the body, 
which is smaller than the rest. It has in general the appearance of 
those of the larger Tipule. . . . The colour of this nymph is of a 
greyish brown, darker on the abdomen. This is divided into eight 
rings, each one having along the hinder edge a fringe of long grey 
hairs; the last ring is armed at the end with six hard and scaly 
points, which serve to push the nymph half out of the earth, according 
to its custom.’’—(C. De G.) 
It was at the end of about a month, or a few days more, that the 
Tabanus fly quitted the pupal envelope, which split all along the upper 
part of the thorax (‘‘ corcelet”’), opening similarly on each side of the 
head, which thus detaches itself from the rest, and leaves free exit for 
the perfect fly. The identical specimen which emerged, and proved to 
be the Tabanus bovinus of Linneus and De Geer,* is figured in plate 
xil. of the ‘Mémoires’ of De Geer (referred to at p. 125); the various 
stages are figured at 6-14; the male 7. bovinus, or Ox Gad Fly, at 
fig. 10, and the female at fig. 11, and from these figures my accom- 
panying figure is precisely copied. 
The above description, from an observer of such high standing, is 
of great value, 
The 7. bovinus, Linn., the Great Ox Gad Fly, is four-fifths of an 
inch or rather more in length, and the length of each wing is about 
* See for description, ‘ Fauna Austriaca; die Fliegen’ (Diptera), by J. Rudolph 
Schiner, vol. i. p. 34, 
