292 Mr Imms, Notes on the Structure and Behaviour of 
Notes on the Structure and Behaviour of the Larva of Anopheles 
maculipennis, Meigen. (Preliminary note.) By A. D. Imms, B.A., 
Christ’s College. (Communicated by Mr A. E. Shipley.) 
[Read 11 February 1907.] 
The larvae of this Mosquito were collected in the neighbour- 
hood of Cambridge during the year 1906. They were met with 
on various dates ranging from May 9th up to August 10th, and 
were obtained from the following four localities : (1) A small 
bricked excavation in the middle of a field, measuring one and 
half feet in cubical dimensions. In addition to larvge of Anopheles, 
the water contained Cyclops, green larvae of Chironomus, a few 
small Coleoptera and confervoid Algae. (2) A roadside pond 
partly covered with Lenina, and containing great numbers of 
Ostracoda, together with red larvae of Chironomus. (3) Still places 
in the backwaters of the Cam. (4) Two ponds situated in a field. 
In one of them they were met with in company with larvae of 
Dixa, Chironomus, and of an undetermined species of Psychodid®. 
The pond also contained numerous dragon-fly larvae belonging to 
several species, together with may-fly larvae and a number of 
small fish (measuring up to about eight inches in length). In the 
other pond there were no fish but great numbers of dragon-fly 
and may-fly larvae, and also larvae of the Stratiornyid fly Odon- 
tomyia. 
The Anopheles larvae were scarce during the whole period, and 
although they were sought for elsewhere none were discovered in 
any other localities around Cambridge. 
An account was also given of the general features of the 
external structure of the larva together with some remarks on the 
habits and behaviour of the animal. The remainder of the paper 
dealt with the internal anatomy of the larva. 
The integument consists of a chitinous cuticle and, underlying 
it, the hypodermis or chitogenous layer. The cuticle is smooth 
and transparent and consists of two layers : an outer and much 
thinner but highly refractive layer, and a relatively thick inner 
stratum, which is much softer and apparently only partially 
chitinised. The hypodermis consists of a single layer of cells 
resting internally on a delicate basement membrane. There 
occurs in many places immediately beneath the hypodermis, and 
adherent to its inner surface, a layer of flattened, irregularly 
shaped cells — the sub-hypodermal cells of Viallanes. 
