MISS EMBLETON ON' CERA.TAPIIIS LATANIiE. 97 



edge of the body, are easily seen because the general colour of the 

 creature is pale yellow. In this condition they move about freely 

 on the plant, but their wanderings are not very extensive, and, 

 in a state of nature, the species could scarcely rely on these young 

 forms as the sole means of dissemination. In their native 

 countries this probably is effected by the winged forms. Later 

 on the early form becomes covered M'ith a powdery white secre- 

 tion, but still there is no definite ring round the margin of the 

 body such as marks the older stages. 



In the active or locomotive early form the antennae are rather 

 stout and blunt ; they are composed of a basal joint and four 

 segments, of which the last isthelongest(P1.12.fig. 4); atits tip it 

 carries several setae and a hook or claw, and there are, in addition, 

 one or two setse on each of the other segments. The last three 

 joints of the antennae are ringed (PI. 12. figs. 3, 5). Between 

 the antennse, on the front of the head, are two small horns in all 

 the specimens I have seen, and in all forms according to Hempel 

 and Lichtenstein ; but Signoret * states that in some young 

 there are no traces of these horns, and suggests that this may 

 be a sexual difference f. In this early condition the body is 

 elongated and the dorsum is but slightly convex ; the head and 

 thorax make up almost one-half of the length of the body, beino" 

 clearly marked off from the abdomen by a groove ; the articu- 

 lation of the body is very obvious at this stage. The legs are 

 not yet hidden by the marginal waxy secretion, which makes its 

 appearance later. The tarsi are two-jointed, and are armed 

 with setae, and end with two strong recurved bristles or claws ; 

 all the segments bear scattered setae, and in all respects are 

 formed normally as in Aphis. The rostrum is proportionately 

 longer in this stage than it is in the adult, for it reaches beyond 

 the posterior coxae ; the basal section is bulbous, and the third 

 and terminal joint is pointed ; each of the first two parts bears 

 a pair of setai, while the third, or last, is provided with two 

 pair'?. 



This form is succeeded by one of an ochreous green colour, 

 larger in size, and in which the body has developed, round the 

 margin, the ring of tubercles from which, later, the fringe of 



* Ann. Soc. Ent. France, 4' ser. viii. (1868) p. 400. 

 t See footnote, p. 94, 



