EXPLANATION OP TEEMS. 3 



to be replaced by a smooth rounded protuberance behind the eye. (Plate 

 i., Fig. 14, oc. ; Plate viii., Fig. 2, k, m; Plate xxi., Fig. 2, 6.) 



Ovisac. The cottony bag or nest formed by certain species of Lecanidina anfl 

 CoccidincR for the reception of their eggs. (Plate xii., Fig. 1, a, 6; c; 

 Plate xix., a, 6, c.) 



Peduncle, pedunculated. A stalk ; stalked. 



Pellicle. The skin of an earlier stage, cast off at each metamorphosis ; used by 

 the DiaspidincR and by one genus of LecanidincB in the formation of the 

 puparium or test. (Plate i., Fig. 3, a, b, Plate vii., Fig. 2, 6.) 



Polymerous. Many-jointed. 



pa. The last stage of the male insect before emerging winged. 



Puparium. The shield, covering, or " scale " of the Diaspidincs. (Plate i., Fig. 

 3, e ; Plates iv., v., vi.) 



Rostral setce. Three or, in a few cases, four long, fine, curling, tubular bristles 

 springing from the rostrum, and often passing through a mentum ; used for 

 insertion into the tissues of a plant and sucking their contents. (Plate i., 

 Fig. 5 ; Plate vi., only one being here shown, from the smallness of the 

 drawings.) 



Ilostrum. A more or less conical, tubular, projecting organ, or beak, protruding 

 from the underside of the cephalic region, or between the first pair of feet. 

 It is absent in the adult female Ccelostoma. It is the " mouth" of the insect. 

 (Plate i., Fig. 5 ; Plate iv., Fig. 5.) 



Sac. The cottony, bag-like covering or nest produced by the spinnerets and 

 concealing the insect in many of the Coccidincc and some Lecanidina. 

 (Plate xv., Fig. 1. c; Fig. 2, b.) 



Scale. The shield or puparium of the Diaspidincn. The word is commonly 

 used to designate the outward appearance of insects of the whole family, 

 which are indiscriminately called " scale-insects," although many of them 

 form no shield whatever. 



Secretion may be of various kinds. It is matter produced by internal organs, and 

 expelled through the " spinnerets." In the Diaspidina the secreted portion 

 of the puparium (that is, all except the pellicles) is made up of fine, closely- 

 woven fibres, forming the "scale." In the LccanidincB it probably exudes 

 originally as fine fibres, but these become agglomerated in some cases in a 

 waxy or horny mass, or in others are loosely collected as cotton. In the 

 Coccidince the secretion is usually cottony, or powdery like meal. 

 Ccclostoma secretes all three wax, cotton, and meal. In some instances, 

 as in Carter-La lacca, of Africa, the wax, called " shellac," is abundant 

 enough to be commercially valuable ; or, as in the Chinese Ericerus Pe-la 

 it can be used for making candles. 



Seta. A bristle a long stiff hair. 



Setose. Bearing a few bristles. 



Spinnerets. Organs observed in various parts of the body, producing the waxy, 

 'cottony, or mealy matter. They consist of cylindrical internal tubes, some- 

 times ending on the skin, sometimes protruding outside it in the form of 

 tubes, spines, or conical hairs. In the former case the orifices show them to be 

 in some instances simple, and in others compound tubes.* In the Diaspidince, 

 besides being scattered over the body, the spinnerets are arranged in groups 

 on the last abdominal segment, and these groups afford excellent characters 



* Minute anatomical details are unsuitable for this work. The student may consult 

 Targioni-Tozzetti, " Studie sulle Cocciuiglie," cap. ii., p. 20. 



