412 NEW YORK STATE MUSEUM 
bottom, jerking its body rapidly from one side to the other. It 
appears to be neavier than water, for sometimes it may be seen 
to descend quietly, apparently without motion; though, in order — 
to rise, it “ wriggles ” to the surface. In the full grown larva 
the head, more or less rounded, is large, usually nearly as wide 
as the thorax from which it is separated by a narrow neck. 
The antenna, which arises from a slight prominence a little in 
front of the eye, consists of a single elongate shaft, with a short 
terminal joint (which appears to be annulated), several bristles 
and jointed hairs at the end of the first joint, and a tuft of 
hairs at about the middle of the shaft. Projecting from the 
middle of the anterior end of the head is a complex arrangement 
ef hairs which spring from two folded ridges one on each side’ 
of the ventral surface of the labrum [pl.48, fig:5]. The length 
of the hairs varies with the species. Meinert [De Hucephale 
Myggelarver| speaks of this as a whorl, or rotatory organ, as he 
believes that it is by the vibrations of these bristles that the 
food is directed into the mouth. The greater part of the upper 
surface of the head is formed of a single plate which Meimert 
[loc. cit.| calls the dorsal surface of the third metamere. In 
front of this is a short, broad plate (“scutum of the second 
metamere,” Meinert), called the clypeus by Giles [Mosquitoes]. 
[pl.44, fig.8c] 
Attached to the anterior margin of the latter is the round 
prominence covered with hairs; this is the labium [pl.44, fig.8] 
or “scutum of the first metamere” [Meinert]. If the front 
part of the dorsal surface of the head be removed and turned 
ventral surface uppermost [p1.43, fig.5], the two fans or rota- 
tory organs [fig.5f] may be seen, mesad and caudad of which — 
are two tufts of hair projecting caudad. Between the latter is 
a rounded process on which are from two to four spines. This 
process together with the two tufts of hair, I believe to be the 
epipharynx[e]. 
The eyes are large and placed laterally, behind which and 
lying close to, may usually be seen a small ocellus. On each 
side of the mouth opening, ventrad of the fans, are the man- 
dibles; stout, quadrangular pieces with a number of sharp teeth, 
at the cephalic end with two stout spines curved mesad, a row 
of hairs arranged on a ridge or keel overhanging the teeth and 
another row of long hairs arranged on the posterior margin 
[pl.45, fig.1, 2]. <A fingerlike process with hair at its apex pro- 
jects mesad from the mesocaudal margin [fig. 2a]. Ventrad of 
the mandibles are the maxillae [p1l.48, fig.4¢]. These are also 
indicated by dotted lines under the mandibles [m] on right hand 
side, the figure being a dorsal view of the lower half of the head, 
