DEER FOREST FLY. 63 
laying not an ege, or anything looking like a maggot or larva, but a 
puparium, or chrysalis-case, in which the insect matures, and from 
which it presently comes out as a perfect fly. It is very like our 
common Forest Fly, H. equina, in general appearance,—that is, it is 
flat in shape, and horny in texture, and with the two wings (when 
these are present) laid flat on the back, slightly overlapping each other 
at the inner edges, and projecting much beyond the tip of the tail,— 
but is a good deal smaller. The Forest Fly is about a quarter of an 
inch in length, whilst the Deer Forest Fly is only about one-sixth of 
an inch in length from head to tail. My largest specimens are slightly 
longer, and from front of head to tip of wings, when laid at rest, they 
measure just four lines. The two kinds may be clearly distinguished 
by the veining of the wings (see figures, p. 60 and below). 
Hrppoposca EQUINA.—1 and 2, nat. size and magnified from life; 3, pupa 
removed from puparium (after Réaumur). Puparium nat. size and magnified, 
before complete colouration. 
The above figure of our common Forest Fly, especially trouble- 
some to Horses in the New Forest, is added to give opportunity of 
comparison with L. cervi, especially in the neuration of the wings. 
The general colouring of L. cervi is of a horny brown or yellow; 
the head shiny yellowish, with the top of the head-and the pits of the 
horns (antennee) black brown; mouth parts brown. ‘Thorax flat, 
chiefly brown, and with small bristly warts. Abdomen yellowish or 
brown, covered with very minute warts bearing bristles, and somewhat 
variable in shape; small in the males, and with the rings bristly at 
the hinder edges, somewhat cylindrical, or inclining to be conical (at 
the base almost pedunculated); larger at the extremity in the females, 
and more of the shape of Olfersia. Legs chiefly yellow; the thighs 
short and thick, it is very noticeably the case with the foremost pair ; 
legs hairy, especially the hinder pair, which are greatly beset with thick 
bristly hairs. Claws black, long, curved and horny, each with a 
somewhat thumb-shaped much shorter claw at its base, and the 
