Characters and Classification. 1 5 



4. The absence of any mouth or feeding apparatus in the 



adult males, which are instead usually supplied with large 



supplementary eyes (//. W. fig. 5). 

 There are insects belonging to the Psyllidce and Aleurodidcz 

 that very closely resemble some Coccidai in outward appearance ; 

 but an examination of the above characters will at once enable an 

 observer to separate them, the members of both those families 

 possessing two claws on the feet, and having four wings in the 

 adult stages of both sexes. The single-clawed foot of the Coccidae, 

 though not quite a unique character among insects, will be found 

 almost sufficient in itself to distinguish a Coccid from any other 

 insect that might otherwise be mistaken for one of this family. 

 Other general characters belonging to the family are : — 



5. The absence of any definite boundary between the head and 



thorax in the female (//. I. fig. 10). 



6. The rostrum, or mouth-parts, situate far back on the under 



surface of the insect between — or even behind — the inser- 

 tion of the first pair of legs. 



7. The secretion in greater or less quantity of waxy, fibrous, or 



resinous matter. 



The life-history and metamorphosis of the Coccidce vary some- 

 what in the several sub-families and, together with the more 

 specialised characters, may be more conveniently described in the 

 chapters dealing separately with those sub-families. 



The family Coccidse has been variously divided into several 

 sub -families varying in number from the four of Signoret — 

 DiaspidcE, Brachyscelidce, LecaniidcE, and Coccidce — to the ten divi- 

 sions in Professor Cockerell's latest Check List,' viz., MonopJdebince^ 

 PorpJiyropJwrince, Coccince^ Hei/iicoccincu, OrtheziincE, Asterolecaniincs, 

 BracJiyscelincE, Idiococcince, Lecaniincs, and Diaspince. Of this larger 

 number I should be inclined to include the PorphyropJiorimc with 

 the MonopJiebincB. Judging from Signoret's description, the cha- 

 racters of both male and female of the genus Po^'pJiyropJiora point 

 to its close alliance with Ccelostoma of Maskell. Nor does the 

 separation of the Asterolccaniincs from the CoccincB (as generally 

 constituted) seem necessary. The principal difference appears to 

 lie in the nature of the secreted test, which in Astet'olccaniiuii or 

 PlancJwnia is of a transparent horny texture through which the 

 body of the insect can be plainly discerned, while in the majority 

 of the Coccinse the sacs are formed of an opaque felted or woolly 

 secretion. 



