9°6] MITCUKLI.—MOL’IH J\4RTS OF MOSQL J'IO I.ARI AF. 
19 
feeds at the bottom of the hollow ; the antennae, mandible and maxilla are all 
typical of this habit. To have such a type of mouth parts the larvae need not 
necessarily be bottom feeders ; they may brush over the sides of a tank or float- 
ing or half-submerged objects, grasses, spirogyra, etc. There are maxillae which 
seem transitional, though there are only the two types of mandibles; and there 
are in some maxillae peculiar developments of the lateral hairs, which are jirob- 
ly related to some peculiar habit of feeding, or character of food. 
.\mong the non-insectivorous larvae is one, Deinocet ites cancer, that so dis- 
tinctly and strikingly, in .several respects, departs from the ordinary type of larvae 
as, so the writer believes, to justify its being placed in a new sub-family, Dkino- 
CERITINAK. The head is sub-circular and is characterized by an angular projec- 
tion of the chitin caudad of the base of each antenna. This lateral angle forms 
a groove, running on the ventral side of the head, in which groove the basal por- 
tion of the lateral aspect of the mandible moves in and out, so as to be visible 
from above, a thing which, so far as the writer knows, exists in no other culicid 
larva. The anal gills are entirely absent. 
The maxilla affords no striking departure from the tvpe, it being in general 
that of a larva feeding on floating objects. 
The labial plate is different from others in that the teeth, instead of being 
broad at the base and coming gradually to a distinctly narrow point (with hut 
few exceptions ), are but little narrowed until they abruptly point off, are very- 
long for their width and, especially, are all separated from each other by a space 
of more than their width, while the two basal are very much longer than any 
but the central (which is about twice the length of the rest), and are set caudad 
from the base of the next by about their own length. 
The mandible is like no other (see fig. 3 ). The biting part is three, weak 
teeth, not heavily chitinised (the whole larva is almost transparent), set in a de- 
cidedly receding row. Normally, the non-insectivorous larvae have four teeth, not 
receding very much. The projection just below the teeth, instead of being about 
twice as long as wide, and having an “under jaw,” is fully six times as long as 
wide, the tip pointed and bent down for about one-fourth the length. The mar- 
ginal comb is nine short, sharp, stright spines. The chopper-like part is a sort of 
narrow hook, finely serrate at the distal end. There is a third articulate spine, 
shorter than the others, between the usual two, an odd number in this place being 
very unusual. Hut the distinguishing feature is the caudal ];ortion of the lateral 
aspect, fn other mandibles, so far as the writer can ascertain, this part forms an 
even, continuous curve with the rest of the mandible body and bears a very few 
minute spines, or (as in Anopheles), a row of fringed hairs. In D. or/zre/' this 
portion of the mandible is produced, and in shape is like the thumb held on a 
plane with the hand and flexed at the second joint. The part flexed in the man- 
