40 Transactions. — Zoology. 



^^in., but shrivelling at gestation ; the anterior region is 

 smooth, the abdomen indistinctly segmented and roughly 

 wrinkled. Antennae very small, almost atrophied, sharply 

 conical, the joints indistinct, but apparently four or five in 

 number; on the last joint are a few hairs. Feet entirely 

 absent. Eostrum rather large ; mentum conical and dimerous. 

 There are four large spiracles on the anterior regioii, each 

 bearing at the orifice a ring of small circular glands, and near 

 the posterior pair are two patches containing large numbers 

 of similar but much smaller glands. Anogenital orifice simple 

 and hairless, with a tubular organ leading to it, which ap- 

 pears to bear at its interior end a number of circular glands. 

 Epidermis covered with great numbers of circular multilocular 

 spinnerets, which are small and scattered on the light-coloured 

 anterior region, but larger and much more numerous on the 

 dark abdominal portion ; they are interspersed with very 

 minute, short, slender, spiny hairs. 



Female of the second stage red in colour, globular, verj' 

 indistinctly segmented ; the abdominal region is rather darker 

 in colour than the rest : diameter about -^-V^^- Antennae short, 

 conical, of five joints, subequal in length, but varying in thick- 

 ness. The feet are somewhat peculiar, having usually a soft, 

 slender, weakly appearance, with a very slender femur (as in 

 fig. 17) and an almost setose claw ; but the anterior pair are 

 sometimes more normal (as in fig. 18) ; there seem to be 

 no digitules. Anogenital ring compound, with apparently 

 only two short hairs. Spinnerets as in the adult, but less 

 numerous. 



Larva yellow, elongated, active ; length about -§^1x1. ; ellij)- 

 tical, segmented. Abdomen rounded, with two very small 

 median anal tubercles, each bearing three short hairs, and 

 above them two others equally small, each bearing a long seta. 

 Antennae of six joints, the first five short and subequal, the 

 sixth fusiform, as long as any three of the others, and bearing 

 some longish hairs. Feet rather thick ; digitules fine hairs. 

 Eostrum large ; mentum long, conical, and dimerous. 



Hah. In Australia, on Casitarina quadrivalvis : specimens 

 from Mr. French. All the individuals observed occupied posi- 

 tions amongst the small scales clothing the bases of the long 

 pointed galls formed bj' the next insect to be described, 

 Cylindrococcus. This was the case with more than twenty 

 specimens received, and I have failed to find any on other 

 parts of the plant. This association at first led me to think 

 that there might be some connection between the two, even if 

 this external insect were not somehow an immature form of 

 the other : the suspicion was strengthened by finding, as men- 

 tioned below, two specimens of the second stage inside the 

 galls. But, later, I obtained a specimen in the act of gesta- 



