2. Rhizococcus fossor, sp. nov. Figs. 36–38. Adult female (fig. 36) greenish yellow in colour, sometimes brown, almost circular in outline, flat beneath and slightly convex above: length about 1/15 inch. In the last stage, after gestation it becomes dark brown. The cephalic part is smooth; the remainder segmented. The abdomen ends in two very small anal tubercles, which are nevertheless somewhat conspicuous on account of their brown colour. Between them there protudes a long thick pencil of white cotton, which is resolvable into six. Antennæ (fig. 37) short, with six joints, the last joint bearing several long hairs. Feet very small; the femur rather thick: the tibia is shorter than the tarsus by about one-third: the four digitules are long fine hairs. The anal tubercles have not terminal setæ; and I can only make out four hairs on the anal ring. A row of a few conical spines, set far apart, runs round the edge of the body, but I can see none elsewhere, nor any circular spinnerets. There is no sign of a sac in any stage. In the second stage the insect is oval, flatter than the adult, and of a rich golden colour: length about 1/40 inch. The segments of the body are somewhat more distinct than in the adult. The anal tubercles are proportionately larger, and bear terminal setæ. Antennæ longer than in the adult, with six joints. Feet also longer. All round the edge runs a row of conical spines, set more closely than in the adult; and from each of these springs a long curly tube of white cotton, making a kind of fringe to the body; each tube is a little dilated at the end, and then tapers to a narrow point (fig. 38). The base of each conical spine is a somewhat large tubercle. The young insect has the general form of the young Eriococcus hoheriæ: colour yellow; length about 1/60 inch. Antennæ as in adult, with six joints. The feet are somewhat large. Anal tubercles thick, bearing a terminal seta and one shorter hair. Along the edge of the body is the usual row of conical spines, set somewhat far apart, and four other longitudinal rows are seen on the surface. The mentum is large and, I think, di-merous. This insect is viviparous. The females are often full of young larvæ, and, as these are born, they are sheltered in a cavity beneath the mother, as in some of the Lecanidæ. They do not remain there long, but soon begin their travels, and move rapidly. The male insect is red in colour, about 1/30 inch in length, undergoing its last transformation in a minute, white, cottony, oval sac. Antennæ of nine joints: the first two short and thick, the third very long and slender, the fourth, fifth, sixth, and seventh about half as long as the third, thicker and rounder, the eighth rather shorter, and the ninth very short and nearly globular. All the joints have hairs. Legs slender: the tarsus