Maskell. — Oil Coccididct!. 143 



The size of the cephahc segment in this insect is pecuhai*. 

 Had there been any sign of a sac in the adult I should have 

 placed the species in the genus Eriococcus, near E. hoherice, 

 mihi, which also has a very large cephalic segment ; but the 

 adult exhibits no cottony sac. The variable antennae are ab- 

 normal. Signoret's original genus Rhizococcus was formed to 

 include B. gnidii, a European insect having antennae of seven 

 joints : I have added B. celmisic? (1883) and B. fossor (1883), 

 with antennae of six joints ; and I now include B. totarce, 

 where the joints are often five, for in all other respects — form, 

 tubercles, anogenital ring, absence of sac, Ac. — it agrees per- 

 fectly with Bhizococcus. 



Rhizococcus pulchellus, sp. nov. Plate YIL, figs. 1-5. 



Adult female green, or sometimes dull-red or yellowish in 

 colour; general form elliptical; length about ^Vn. as a rule, 

 but some specimens xV'^- ' segmented, the segments not 

 very distinct ; body longitudinally corrugated wich four shallow 

 depressions ; covered with many conical spines, from which 

 spring on the dorsum sliort glassy cylindrical tubes, giving it 

 a numerously-bristled appearance, and on the edges much 

 longer tubes which form a fringe. Antenna of seven subequal 

 joints. Feet normal of the genus. Anal tubercles small, 

 setiferous ; anogenital ring with eight hairs. 



Female of second stage bright-green in colour, longitudinally 

 corrugated as the adult, the elevated portions of a lighter 

 green than the depressions ; elliptical, flattish, segmented ; 

 length about j^in. The ventral surface is convex, the 

 insect forming a shallow depression in the leaf it lives on. All 

 the segments bear very numerous, large, conical spines, from 

 which spring dorsal and marginal glassy white tubes, longer 

 than those of the adult, so that the insect appears studded 

 with silvery spikes and with a long fringe ; the marginal spines 

 are a good deal larger than the dorsal ones. Antennae of six 

 joints, the fourth and fifth rather shorter than the rest. Feet 

 rather large ; on the trochanter a long seta ; digitules slender, 

 but the lower pair rather more dilated at the end than the 

 upper. Mentum dimerous ; there appear to be four rostral 

 setee. Anal tubercles rather large, setiferous, with a strong 

 spine near the end. 



Larva elliptical ; colour green with brownish patches ; 

 length about ^\yin. ; dorsum flat, slightly corrugated longi- 

 tudinally ; ventral region convex. Antennas of six joints. 

 Segments bearing spines, but less numerously than in the later 

 stages ; the spines are arranged in eight longitudmal rows 

 (including the two marginal series), and bear glassy tubes. 

 On the last four abdominal segments there are also rows of 

 fine small spiny hairs — dorsally, two in the middle of each 



