288 
Head (figs. 9—10), subquadrate, much wider than long; eyes 
very small, almost rudimentary, as compared with the eyes of the 
Culex-larvæ. HH. D.K. (1915 p. 507) state, that the eyes in the 
larva of M. perturbans are rudimentary; that in M. ditillans they 
are placed upon slight prominences near the posterior angles; 
further that the anterior division of the eye is narrow, transverse, 
curving around from upper to under surface. The eyes of the 
Danish larva are quite undivided and probably a little more devel- 
oped than in the American larvæ. Antennæ of a rather peculiar 
structure, very long with a large hair-tuft beyond the middle arising 
from a notch; especially the terminal portion is very long and 
much drawn out, but it is thicker than in the American larvæ; 
two of the terminal hairs situated not far beyond the tuft. The 
apex carries two inconspicuous hairs, an outer hair very hyaline 
and an inner one more strongly chitinized and needle-shaped. On 
the dorsal surface of the head the scythe-shaped areas (Thom p- 
son 1904 p. 168) are strongly developed; dorsal hairs of the head 
all in multiple groups. Near the median line of the head we find 
two hairtufts, each with five long bristles; more laterally and in 
front there are two other tufts, each with about nine bristles. The 
head carries further four pairs of smaller tufts; the sides two pairs, 
one behind the antennæ, the other behind the eyes; near the hind 
margin of the head we find two long single and strong bristles. 
On the anterior border of the - epistome (clypeus by H. D. K.) 
there are two other bristles, but these are shorter and stronger. 
According to my opinion the labrum (figs. 11 and 12) of the 
larvæ of the Culicidæ is three-lobed, consisting of a median lobe 
(fig. 12 b) commonly called /abrum, scutum of the first metamer 
by Meinert, palatum by Thompson (1904 p. 169) and two 
lateral lobes (fig. 12 c) which are supported by a somewhat com- 
plicated system of black-pigmented apodemes, which are connected 
with the so-called blackspot areas (Thompson 1904 p. 169, fig. 
12d): spots of thicker chitin "which involves part of the ventral 
face of the rostrum and bear a conspicuous patch of pigment". 
The two lateral lobes carry the two flabellæ, the well known 
brushes of the mosquito larvæ; they partly catch the animalcules 
and microscopical plants, partly they are locomotory organs. The 
structure as well as the use of the flabellæ of the Culicid-larvæ 
