160 



A. T. STANTON. 



position at the water surface for breathing and feeding. The accompanying diagram 

 (fig. 1) shows the position of these appendages on the upper or dorsal surface of the 

 head in an Anopheles. A and B are the inner and outer pairs of anterior clypeal 

 hairs, C the pair of posterior clypeal hairs ; these hairs differ notably in form and 

 position in different species and in the same species at different stages of its growth. 

 D is one of a row of six frontal hairs between the bases of the antennae, E and F are 

 the inner and outer pairs of occipital hairs ; in a few species only are these groups 

 of value for identification. There is also present in certain species a branched hair 

 on the shaft of the antenna. 



It is not only in Anopheles that the form and arrangement of the hairs on the 

 dorsum of the larval head are characteristic ; in other groups of Culicidae they 

 are also of generic and specific value. In Malayan species of the Cuhcine genus 



^A \^. 



Fig. 2. Larva of Anopheles sinensis, Wied. ; a, newly hatched ; 

 h, after first moult ; c, after second moult. 



Stegomyia and of the nearly related genera Armigeres, Ochlerotatus and Danielsia, 

 the general arrangement of larval head hairs is the same, while their form differs 

 in the different species. Larvae of the genus Uranotaenia are characterised by the 

 presence of large spinous setae on the dorsum of the head. 



Growth Changes in Anopheline Larvae. 



During the growth of Anophehne larvae of all species notable changes take place 

 in the form and arrangement of the clypeal hairs of the head and in the leaflets of the 

 thorax and abdomen. Drawings of the larvae of Anopheles sinensis, Wied., at different 



