CELASTRINA ARGIOLUS. 443 



of tubercles i, iv-f-v, vi, and vii, in having them both rather 

 more abundant and rather larger than in the regions between. 

 The prolegs have the usual anterior and posterior pads, each of 

 which has eight or nine large hooks (0*08mm., or O09mm. long), 

 and nine or ten little more than half their length, alternating with 

 them. The claspers are very similar, but the hooks are a little larger 

 and the posterior set are more numerous (20 to 25 in different 

 specimens) (Chapman). 



Special prothoracic larval hairs. — We have, on the prothorax, 

 most conspicuously in the last larval instar, a pair of hairs differing 

 very much from all the others anywhere on the larva ; each hair is 

 nearly as obvious in the preceding (penultimate) instar, when found, 

 but does not compel notice as in the last skin, and, tracing it back, it 

 is found in the 2nd instar, and appears to correspond with one in the 

 1st instar, which, in examining that stage, attracted no attention ; it 

 is the smallest hair on the prothoracic plate, occupying its outer 

 posterior corner. In this 1st instar, this hair is very slender, un- 

 spiculate, of uniform width from end to end, and, in length, about 

 O'lmm. ; its base is not raised into the same cone as the others, but 

 has a similarly darkened (the bases of the other hairs in the first stage 

 are .definitely marked off from both hair and skin by dark colouring) 

 area on the flat of the plate, not sharply defined, but fading out at 

 its margin, and the pale circle to which the hair is articulated is larger, 

 four or five times the diameter of the hair instead of much the same 

 as in the ordinary hair. In the second instar, this hair occupies the 

 same position so far as the prothoracic plate can be defined, and has 

 much the same character. It is small, slender, but enlarging a little 

 upwards, and smooth ; its base is remarkable in not being stellate, like 

 that of all other hairs, but merely a dark rounded elevation of the 

 plate itself, and not a separate structure, nevertheless, it is inconspicuous 

 amongst the other hairs, chiefly owing to its small size. In the penul- 

 timate stage (pi. xxv., fig. 1), it is very conspicuous (when looked for) by its 

 base being brown, the other hairs and bases being colourless. The hair is 

 about 014mm. long, and the other characters are as already described in 

 the second stadium. One may believe, taking these hairs as indications, 

 that one sees the outline of the plate in this third stage, marked by 

 a trifling difference in tone. In the last stage, they may be seen by 

 aid of a hand-lens, as two brown dots - 5mm. apart. Magnified, they 

 look quite unrelated to the beautiful, nearly stellate, hair-bases that 

 closely surround them. Instead of being superficial to the skin, and 

 articulated to the surface, like the other hair-bases, this brown base is 

 a hemispherical eminence beneath the skin, and the skin -points are 

 seen regularly arranged, superficial to it, the central ones closer 

 together than elsewhere, and tinted brown like the hair-bases, wanting 

 only in a narrow circle round the central pale spot, from which the 

 hair arises. The hair itself is very long and slender, colourless, 

 0-4mm. long, the hairs about it being at most O'lmm. Towards the 

 end, it expands into a spathulate process (or clublike and rounded 

 during life ?) on which the very faintest traces of points are seen (or 

 suspected ?), very different from the spicule of the ordinary short hairs. 

 No trace of this very remarkable hair, or anything to represent it, can 

 be found on the pupa (Chapman). 



Variation of larva. — The larva varies very considerably in colour, 



