54 



F. W. EDWARDS — FURTHER NOTES ON AFRICAN CULICTDAE. 



reddish thorax and the venation generally give fairly safe elues to the specific 

 identity. The only absolutely reliable character, however, is the structure of the 

 male genitalia (fig. 3). C. quasiguiarti was certainly described from females of 

 C. pipicns ; the type of C. zombaensis is either the dark form of C. pipiens 

 referred to above, or a corresponding variety of C. fatigans, the venation more 

 resembling that of the last-named species, though I prefer to regard it as the 

 former ; it is, however, a matter of no consequence, as both species occur in 

 East Africa. 



In mounting genitalia I find it advantageous to use the following method : 

 The tip of the abdomen is carefully snipped off with a pair of sharp-pointed 

 scissors, and placed in 10 per cent, caustic potash, which is then just brought to 

 the boil. The specimen is then washed well with water, transferred to absolute 



Fig. 3. — Culex pipiens, L. 



Basal parts (harpes and harpagones) of hypopygium from above. The large side pieces are 

 not shown, as they exactly resemble those of C. fatigans, and are essentially similar to those of 

 C. pallidocephalus, except that their lateral processes bear only one leaf -like appendage. 



alcohol for two or three minutes, thence to clove oil, where the hypopygium is 

 separated from the terminal abdominal segments, and is then transferred to a 

 drop of stiff Canada balsam on a small strip of transparent celluloid, without 

 any coverslip, which is placed on the pin below the stage bearing the insect 

 from which the genitalia were removed. The hypopygium should be carefully 

 adjusted when placed in the balsam, so that good dorsal and ventral views 

 can be obtained, either for examination or for drawing. If this is not done, 

 however, it is quite easy to remount the specimen at any time. 



I find that if specimens of complex genitalia are mounted on ordinary glass 

 slides with coverslips over them, the arrangement of the parts is apt to become 

 so much altered that without considerable experience they are hardly recognisable. 

 The figures given by Messrs. Dyar & Knab for Culex pipiens and C. fatigans 

 (Proc. Ent. Soc. Wash. 1909, pi. 2, fig. 4, and pi. 1, fig. 1) were made from slide 

 preparations, and the differences between them and those here given are mainly 



