234 



6. The Thorax. — The thorax, in the adult 

 larva is large and globular. ^ In the young larva^ 

 it is not, so broad as the head,,Jput beconiesi pro-, 

 portionately larger as the larva, advances, in, age., 

 Numerous hairs arise from the front and sides of 

 the thorax. None of these vary perceptibly .in^ 

 different species. A number of large hairs arising 

 fro,i;n papillae on the lower surface are capable, of' 

 being used almost as a means of progression when 

 th;e larva is in very shallow water. ; 



(a) Observe on the dorsum of the thorax < a 

 short but extremely stout and strong hair, unlike 

 the others, projecting outwards and forwards. 



; (b) A flap -like body may, with ■ careful 

 focussing, be seen lying at the base of the most 

 anterior hairs on either side. 



(c) In some species of Anophelines a single pair 

 of palmate hairs, similar to those on the abdo- 

 minal segments, are found upon the thorax. In 

 others they are rudimentary or absent. The 

 presence of well- developed palmate hairs on the 

 thorax is of specific importance. 



(i) It is well developed and functionally 

 active in M. culicifactes, M. listoni, P. jeyporensis. 



(ii) ■ It is rudimentary or absent in all other 

 larvae as yet described. ' ' . 



7. The Abdomen. — The first seven segments are 

 very similar in shape. The eighth carries the 

 opening of the air-tube, and the ninth some 

 curious papillae and large hairs. 



Each of the first two segments carries on each 

 side a pair of long feathered hairs. The third 

 carries a single similar hair. On the other 

 segments there are much smaller and unfeathered 

 hairs. On all the segmei;its there are groups of 



