46 • [July. 



those of the females, and are often considerably smaller, besides being 

 frequently of a purer white. For instance, the female scale of Aspi- 

 diotus ostrearformis is more or less circular, and of an ashy-grey colour, 

 resembling, as regards shape, that of A. nerii (fig. 6), whilst the male 

 scale is of an oval shape (see fig. 5). The female scale of Aspidiotus 

 zonatus is circular, whilst the male is an elongated-oval (see fig. 3). 

 Again, the female scale of Diaspis ostreceforinis is more or less circular, 

 in shape and colour much like the A. nerii, whilst that of the male is 

 small, linear, and snowy-white, as shown in fig. 2. In some species 

 (e. g., Mytilaspis pomorum) the male scale differs from the female only 

 in being smaller, and in having one instead of two exuviae. 



Eig. 4 represents the scale of the female Mytilaspis pomorum, 

 found in abundance on the bark of apple, plum, &c, kindly sent me 

 by Mr. Douglas, and which was much covered with "rust" and secre- 

 tion, so that the second larval skin could not be seen ; but since 

 making the drawing, I have found some of the same species on the 

 Calluna vulgaris in this locality, which showed more plainly the second 

 skin, of a brown-russet colour. The scale of this species is of a dark 

 colour, shiny, almost resembling a steel-blue. In the genus Tlhleria, 

 Comstock (= Fiorinia, Targioni-Tozzetti) there is but little scale, the 

 first larval skin lying quite at the extremity of the second, which is 

 very large, and this is merely skirted all round with a white filamentous 

 belt, which is in fact the scale. 



Fig. 1 represents the type of this genus, viz., Uhleria camellice, 

 Comst., which is very closely allied to, and may possibly prove identical 

 with, the Fiorinia pellucida, Targ.-Tozz. The insect itself lies under 

 the second larval skin, and in this species is only about half the length 

 of the second skin. It is not unusual in many species to find the 

 adult insect considerably smaller than the second skin, and perhaps in 

 this way it finds itself better protected from cold and other external 

 enemies. ]n those species where the first larval skin is situated an- 

 terior to the scale, the antennae of the first skin are usually found 

 distended, as shown in figs. 1 and 2 ; and although I have not observed 

 this in the case of Mytilaspis pomorum (fig. 4), it will be found in 

 some of the other species of this genus (e. g., M. pandani). I' have 

 never observed this feature in those species in which the exuvise are 

 situated within the limits of the scale. As has been observed above, 

 the eyes, legs, and antenna; of the Diaspinae (with possibly one or two 

 exceptions) are disposed of after the first stage of the insect's life, but 

 the second cast skin may always be distinguished from the real insect 

 by the position of the haustellum, which, in the cast skin, is almost 



