PUPAL STAGES OF AVEST AFRICAN CULICID.E. 9 



1. The abdomen will be measured from the base o£ the thorax to the end 

 of the eiohth seoment ; the anal seoinent beino- excluded. 



2. The siphon_, from the ehitinous ring at the base to the tip ; the valves 

 being excluded^, and the breadth being that of the ehitinous ring. 



3. The measurements of the anal segment will be the greatest length and 

 breadth of the ehitinous plate of which it is formed. 



4. To measure the whole larva or pupa, the trough is placed on a metric 

 scale of metal or ivory ; the contained creatures are then arranged on the 

 scale, and the measurements read off w^ith a lens magnifying 12 to 15 

 diameters. In the case of the pupa the only measurement used is the 

 greatest length of the thorax, as the tail varies so much in its curves and 

 positions that no useful comparisons can be made. 



Examination of Living Larvae. 



For this purpose a well made Rousselet live-box, or a compressorium, is 

 necessary; the larva? are transferred with a pipette, and with a little practice 

 it will be found that they can be kept quiet without injury_, and can after 

 examination be returned to an aquarium or other breeding arrangement. 



Characters of various Parts. 

 The Hairs. 



The hairs of aquatic larva3 constitute one of their most striking features, 

 and those of the CuLiciDiE present an extraordinary variety, often affording 

 very beautiful objects for the higher powers of the microscope. For the 

 purposes of determination and comparison, a certain amount of exactness in 

 definition will be found of use. I therefore propose the following : — 



1. A hair is elastic, may be long or short, exceedingly thin or moderately 



stout. 



2. A bristle is not elastic, never very short ; it is stouter than a hair, and 



may be curved, sharp or blunt, or even thickened at its end. 



3. A spine is of any length, it is otherwise a thick bristle which is straight 



and sharply pointed. 

 Hairs may be further subdivided, and I follow the classification of these 

 structures suggested by Nuttall and Shipley. 



a. Feathered hairs. — This term is used when the secondary hairs are all 



in one plane and are very long, as in the thoracic plumes of the 



ANOPHELIN.E (PL VI, fig. 3). 

 ]). Plumose hairs are those in wdiich the secondary hairs are shorter and 



are, or are not, in the same plane : such as the antennal plume in most 



larva3 (PI. I, fig. 1). 

 c. Sahplumose hairs. — Refers to those in which notches can be seen wdth a 



magnification of 60 diameters, but having only very short secondary 



hairs. A rare condition. (PI. Til, fie:. 17.) 



