ASTEROLECANIUM THESII. 155 



of the scale is closed by a thin pellicle. The sides of 

 the scale are approximated in order that they may 

 grasp the thin stem of the food-plant, to which they 

 closely adhere. The closure of the scale causes the 

 insect to be quite enveloped ; after death it becomes 

 shrivelled. . . . There were no eggs or larvae in the 

 scales, but a brown one contained the larva of a 

 parasite that quite filled the space " (Douglas, 1. c.). 

 After the death of the female the ovisac changes to 

 pale ochreous. 



Long, 2-2 '25 mm. 



Adult female (PI. LXII, fig. 16) approximately 

 circular, posterior extremity (PL LXII, fig. 17) sud- 

 denly produced. Rudimentary antennae bearing one 

 long hair and four or five short ones. Mentum doubt- 

 fully biarticulate, short ; rostral filaments (loop) short. 

 Marginal spinnerets (PI. LXII, fig. 18) shaped like the 

 figure 8, and disposed in two rows at the front and 

 sides, but placed alternately as to the respective rows, 

 posteriorly merging into one nearly straight row (fig. 

 18). Anal ring recessed within a larger one, bearing 

 six hairs. Anal lobes rudimentary, each indicated by 

 a single long hair, and between them near the anal 

 orifice are two shorter hairs and several minute ones. 

 Dorsum with numerous long tubular spinnerets, and a 

 few scattered circular spinnerets. 



Habitat. On Thesium humifusum, Isle of Purbeck ; 

 discovered by Mr. Eustace R. Bankes, 12th July, 1892. 

 With the insects, which were forwarded to Mr. J. "W. 

 Douglas, Mr. Bankes sent the following particulars : 

 " While spending the day yesterday in the Isle of 

 Purbeck, in searching for pupae of Cliauliodus in- 

 securellus on the scarce, local, and little-known plant, 

 Thesium humifusum (a parasite on other plants), I 

 found the scale-insects I now send. They were in 

 every case attached to the underside of the twigs, 

 sometimes in a little cluster, generally near the base of 

 the plant, and not easily seen if the plant is examined 

 from the underside " (Douglas, 1. c.). I have seen but 



