66 CHARACTERS AND CLASSIFICATION. 



MALE. 



(1) Wings, when present, two; posterior pair repre- 

 sented by a pair of halteres, the bristles of which 

 fit into a fold or pocket near the base of the wings. 



(2) Segmentation between head and thorax usually 

 distinct. (An exception occurs in the British Aj>lrr<>- 

 coccus frazini, Xewstead, where the boundary between 

 the head, thorax, and abdomen is practically obsolete. 

 The same abnormal character has also been met with 

 in a species from New Zealand and elsewhere.) 



(3) Legs with the tarsi as in the adult 9 . 



(4) Mouth obsolete, one or more pairs of large ocelli 

 usually occupying its position. 



(5) Metamorphosis complete ; mouth organs lost at 

 period of pupation. 



One of the surest marks of distinction lies in the 

 monomerous tarsi and -in^le claw, which, as a rule, 

 will readily separate a Coccid from any of the closely 

 allied families which may otherwise resemble it. 



Both sexes secrete a varying quantity of waxy, mealy, 

 horny, or resinous substance, which may be either 

 attached to the body, as in Dactylopius and (h-lh< 

 form a separat^ shield-like covering, as in the 

 pin& ; a complete fibrous or felted sac, as in 

 etc.; or a resinous cell, as in the foreign genus 

 Tiiclm r<l in. These secret ionary coverings afford valu- 

 able data for the separation of the various sub-families 

 and genera; and the sexual difference, both in form 

 and nature of the secretion, is generally very pro- 

 nounced. 



Taking the family as a whole, both foreign and 

 British, the division of the Coccidse into sub-families 

 has been variously set forth by most of the leading 

 authorities. In this work I have, with slight altera- 

 tions, adopted the very clear and comprehensive divi- 



