79 



/Note two rows of spines, ' the pecten,' on the 

 posterior aspect of the syphon tube, starting from the 

 base and extending a variable distance up the syphon 

 tube ; note that they differ much in number and 

 shape, etc., in different species. In some species (e.g., 

 in cannibal larvae) a large fan of hairs projects pos- 



Fig. 27. Respiratory Syphons of Larvae. 



(i) Stegomyia sp. ; (2) Culex sp. ; (3) Culex with Large Syphon Tube ; 



(4) T aeniorhynchus sp. ; (5) Cannibal Larva (? C. concolor) ; 



(6) Enormous Syphon Tube (one quarter scale of others, 



genus undetermined) ; (7) Spine on Tube seen on 



the flat ; (8) Spine seen sideways 



teriorly in the median line from the syphon tube. In 

 certain species the syphon tube is of enormous size, 

 and may attain to one-third the length of the larva. 

 On the eighth segment at the base of the syphon is a 

 group of scales, the f comb.' It differs much in 



