204 CHAS. K. BKAIN. 



The pygidium (fig. 115) is very much like that of C. fens, but can be readily 

 distinguished by P 4 . There are usually 3 of these plates, of which the first two 

 from L 3 are divided into two parts, the inner half being small and linear, the outer 

 much longer and broadened, reminding one of an inverted Cupressus pyramidalis 

 tree. Small variations are noticeable in the lobes and paraphyses, of which the 

 most striking are : (a) the lobes are normally decidedly notched on their outer 

 margins, the notch being often absent from L x and L 2 in old specimens ; (b) the 

 fourth pair of paraphyses from the middle line are sometimes much broadened 

 near the apex and do not appear to extend to the margin. Very thin, delicate 

 tubular glands numerous. Circumgenital glands in 4 groups : — 



4—5 4—5 



1—3 1—3 



Formula :— P x , L 1; 2P 2 , L 2 , 3P 3 , L 3 , 2-3P 4 . 



Habitat: On guava ; collected by J. W. Hodgson, Barberton, Tvl., 17th June, 

 1915. On palm and rose, Pretoria ; collected by Miss Irapey, April 1916. On 

 umkovoti (Chaetachme aristata, Planch.) Durban, Natal ; collected by C. Fuller. 

 On camellia, Pietermaritzburg ; collected by A. Kelly. On mango, Nelspruit ; 

 collected by J. W. Hodgson. Also on Cupressus macrocarpa, rose, peach, etc., from 

 Cape Town, East London, Kingwilliamstown and Kimberley. 



Collection Nos. : 236, 236a, 242, 244. 



102. Chrysomphalus ( Pseud ischnaspis) corticosus, sp. n. (Plate xii, fig. 119). 



Common Name : South African Obscure Scale. 



Scale of adult $ varying greatly on different host-plants. On smooth-barked 

 plants it is very large and fiat, reaching 3 "2 mm. in diameter, brownish to black in 

 colour, with the blackish exuviae covered. As a rule, however, the scale is almost 

 or entirely covered by the outer layers of bark of the host-plant. On Rhus this is 

 usual, and it has been submitted on many occasions as a burrowing scale. On 

 Robinia the scale takes the greyish appearance of the bark, but the black exuviae 

 are very conspicuous with a greyish white concentric ring. On wild olive, on the 

 other hand, it forms a thick crust of blackish or greyish black scales, which easily 

 flake off. The scale itself, without any admixture of tissues, is pitchy black, with 

 concolorous exuviae. Seen from below the scale is domed and very glossy. The 

 ventral scale is delicate and usually remains on the host-plants. 



The adult $, when alive, is purplish to plum-colour, but turns dull brown when 

 old or dead. The body is broad pear-shaped, about 1"5 mm. long and l - 2 mm. broad. 

 Antennal tubercles small, with one long, curved seta. Parastigmatic glands 0. The 

 arrangement of lobes and plates is very similar to that of obscurus (fig. 121), to which 

 this species is very close. The most striking differences in the pygidium are the 

 longer and stouter paraphyses, the presence of two distinct paraphyses between the 

 median lobes, and the presence of a greater number of dorsal glands. The pygidium 

 is as illustrated (fig. 119). Circumgenital glands in 5 groups : — 



6—9 



17—24 17—24 



9—16 9—16 



