1 6 Characters and Classification. 



This sub-family, Coccince, presents considerable difficulties to 

 the systematist if made to include such divergent forms as typical 

 Coccus on the one hand and Eriococcus, or Dactylopiiis, on the other. 

 The genus Coccus, which must naturally be taken as the type of 

 the sub-family, contains insects possessing neither the anal tubercles 

 nor the setiferous anal ring of the other genera usually associated 

 with it. It might with more justice form the type of a group 

 including Gyninococciis Dougl., Cryptococcns Dougl., Capulinia Sign., 

 and perhaps Xylococcus Low. Mr. Maskell's division oi IdiococcincB 

 is with difficulty separable from such a group, but SpJicerococcus 

 and CylindTococcus contain such abnormal and extraordinary forms 

 that they may conveniently be retained in a separate division. 

 The Dactylopiid group (including Planchouia), characterised by 

 the setiferous anal ring and tubercles, form a natural division 

 which, in the classification adopted below, is called Dactylopiince. 



Conchaspis and Tachardia, two genera at present included in 

 the Coccince and Brachyscelincu respectively, bear such distinct cha- 

 racters in all their stages as to warrant their accommodation in 

 separate sub-orders. 



The following classification is put forward tentatively. I am 

 fully aware of its imperfections ; but by this arrangement the 

 several sub-families not only fall into more or less naturally allied 

 groups, but lend themselves to a convenient system of Synopsis. 



Two primary divisions may be made, according to the presence 

 or absence of compound (facetted) eyes in the adult males. In 

 the majority of the sub-families the male insect possesses four 

 simple eyes, two on the upper and two on the under surface of the 

 head. These are really supplementary eyes, homologous with the 

 ocelli of other insects, the true eyes in these cases being very much 

 reduced, appearing merely as a small colourless tubercle on each 

 side of the head, or entirely obsolete. In the division containing 

 males with compound visual organs, these represent the true eyes 

 occupying their normal position on the sides of the head, while the 

 ocelli are small or altogether wanting. 



Synopsis of Sub-families. 



A. Males with simple eyes. 



a. Abdomen of female terminating in a compound segment 

 (pygidium). Anal orifice without a setiferous ring. 

 (i.) Insects with a separate covering-scale formed entirely of 

 secretionary matter without admixture of the exuviae. 



