52 
A Monograph of Culicidae. 
whole abdomen is flexible, and serves as the swimming organ. 
When at rest the pupa has the two oblique openings of the 
siphons parallel with the surface of the water, and just above the 
surface film. 
According to Hurst,* the ninth segment corresponds to two or 
more segments. The same naturalist points out that “there is 
a large cavity between the lower and hinder portions of the two 
wings, below the hinder part of the thorax and first portion of 
the abdomen, and above the “ mouth parts,” which communicates 
with the cavity of the tracheal system by a pair of stigmata on 
the sides of the first segment of the abdomen. Other stigmata, 
though present, are closed.” Air is, however, only taken in by 
the pupa through the two air-tubes arising from the respiratory 
trumpets. 
The chief peculiarity, then, in the pupa of Culex is the 
presence of the two obliquely opened air-tubes or trumpets. 
Anopheles pupa (Fig- 20).—In Anopheles the pupa is very 
much like Culex , but it is rather more compressed ; the siphons 
(a), however, form the chief difference, for they have a square 
truncated end, and are proportionately much shorter than in 
Culex (b). In colour the pupae of A. maculipennis may be either 
dull brown, grass-green or light yellow-green, with paler wing- 
cases and trumpets; on each side of the fourth to the eighth 
segments is a black spot. They are just as active as in Culex . 
Professor Howard points out that when in the water the 
pupa of Culex is more vertical than that of Anopheles. No 
notes have been sent regarding the pupae of this genus, but 
presumably they vary in colour. 
Moehlonyx pupa (Fig. 19).—In Mochlonyx the pupa again 
only differs slightly from Culex , but can be told at once by certain 
characters, of which the most important is the form of the air 
siphons. In this genus the trumpets are thin, rounded and 
pointed at the end ; the seventh segment is also very much 
larger than in Culex or Anopheles , and the abdominal bristles are 
more scanty. 
Corethra pupa (Fig. 18).—Of quite different appearance is 
the pupa of Corethra , which is nearly straight, not curved as 
* “On the life-history and development of a gnat (Culex).” An. Eept. 
and Trans. Manchester Micro, Society, 1890.. 
