Maskell. — On Neiv Zealand Coccidae. 127 



The number of joints of the antennae, the number and character of the 

 digitules, and the sheath of the penis in the male, are points on which 

 specific and generic distinctions may well be founded ; but the joints of the 

 antennae are often difficult to determine, and various observers may imagine 

 seven joints where others see only six and others eight. An instance of 

 this difficulty is given below, under Ctenochiton verforatus. With regard to 

 the mentum, it seldom happens that this can be thoroughly well examined 

 in an adult or old female. It is usually stated also that a special character 

 of the Lecanidae is the immobility of the adult female. But, first, this is 

 certainly not a distinction from the Diaspidae, for in that group the insects 

 become apodous, and therefore fixed, from an early stage ; and, secondly, 

 no Lecanid is more stationary than Icerya purchasi, an undoubted member 

 of the Coccid group ; for this insect, as soon as it begins to form its pecu- 

 liar ovisac, ceases altogether to move about and simply becomes gradually 

 raised up a tergo. In point of fact, with the exception of the abdominal 

 cleft and lobes, there is probably not any character of the Lecanidae which 

 cannot be found in some one or other of the remaining groups. 



This being so, I would confine the distinguishing character of this 

 group to its abdominal features, and would employ for its subsections the 

 nature of, or the absence of, the secretion produced. In this way the fol- 

 lowing key would show a gradually progressive series, linked with the 

 Diaspidae by Lecanochiton and with the Coccidae through Kermes and 

 PLanchonia. 



2nd. Group. 

 Insects presenting at all stages a cleft at the abdo- 

 minal extremity, and, above it on the dorsal side, 

 two more or less conspicuous and triangular lobes LECANID iE. 



Subsection I. 

 Insects covering themselves with a secretion, com- 

 posed chiefly of waxy, horny or glassy matter ... Lecanio-diaspime. 

 Test horny, partly formed of the second pellicle ... Lecanochiton. 

 Test waxy, with single fringe of broad segments . . . Ctenochiton. 

 Test waxy, produced into radiating branches ... Vinsonia. 



Test waxy, without fringe or branches ... ... Ceroplastes. 



Test waxy, elevated, as if double ... ... ... Fairmairia. 



Test glassy, conical or elongated, elevated, striated 



with air-cells ... ... ... ... ... Inglisia. 



Test agglomerated in a waxy mass containing colonies 



of insects, male and female ... ... ... Garteria. 



Test absent for the female, present and aggregated in 



a waxy mass for the male ... ... ... ,.. Ericerus. 



