ARICIA MEDON. 265 



beginning of each segment and widest at its termination on the 

 penultimate ; on the sides of the 1st to the 6th abdominal segments 

 are double oblique lines slanting backwards and downwards, of paler 

 green in front and darker green behind than that of the ground-colour. 

 At this stage of growth the lateral projecting ridge of swellings broadly 

 pink, with scarcely an indication of a central paler stripe ; the belly 

 and ventral prolegs pale yellowish-green; the true legs flesh-colour; 

 the head black, the base of the papilla flesh-colour and a streak 

 of the same above the mouth. On approaching full growth the 

 oblique stripes gradually disappear, the green colour becomes rather 

 darker ; a pinkish-white stripe runs along the lateral prominences, 

 broadly bordered above by a stripe of rose-pink, and beneath by a 

 broader stripe of still darker pink. The spiracles are. flesh-colour, 

 situated in the upper pink stripe, very minute and inconspicuous. 

 The ventral prolegs green, the true legs pinkish, spotted with brown 

 (Buckler). 



The- following is the larval ontogeny as worked out by Chapman: — 

 First instar. — September 6th, the little larva hatched [September 4th, has 

 now grown a little but barely exceeds a millimetre in length. It is 

 greenish-grey in colour, well matching the whitish undersides of the 

 Heliantheinum leaves, and has a number of black dots, which are hair 

 bases, lenticles and spiracles. The abdominal segments carry i, a 

 long curved hair, spiculated, pale, with a black base ; ii, a shorter 

 hair similarly curved, two large lenticles ; iii, with a straight hair, 

 directed outwards and a little forwards ; the spiracle, and three 

 marginal hairs in a row, diverging, the middle one 1 longest. This 

 description is correct for dorsal portions of 6th abdominal, but those in 

 front differ; the upper lenticle of the 6th, which is posterior to the other, 

 is represented by a small spot, but the upper lenticle corresponds to the 

 lower one of 6th, and has below and behind it another, and below this 

 and behind iii, is a small dot, apparently a hair ; the 7th has a lenticle 

 in place of ii, and no others ; the 8th has above spiracle only i, and a 

 lenticle (ii ?). 



A description from another larva; (several descriptions of these 

 difficult little mites are not undesirable). The larva when hatched 

 is a very small scrap of nearly colourless tissue. When full-fed, 

 its utmost stretch is barely 2mm., body pale ochreous, head and 

 legs black, or legs a little less dark, head 02mm. wide, with a 

 few fine hairs. Neck can be stretched to 0'35mm., between head to 

 first skinpoints of prothorax. Skinpoints are numerous, fine and 

 sharp, but very palely tinted. The hairs and lenticles are very 

 nearly in the arrangement usual in first instar Lyctenids. The chief 

 point of special difference is that instead of the two hairs above the 

 abdominal spiracles (iii?) being both very small, the front one is a 

 large well-developed hair, quite equal to ii in size and length, the 

 the other is small, and in one specimen, is wanting on one side in 

 abdominal segments, 1, 2, 6 and 7, and on the other in 4, 5, 6, 7. 

 Both are absent (as usual) on 8th. 



The prothoracic plate (about 0-14mm. across) has a pair of large 

 lenticles on the front margin with a pair of minute hairs between them, 

 behind them and closer together are a pair of long hairs (02mm. long), a 

 similar pair further back and wider apart, and a small hair towards the 

 outer angle. There are three hairs about 013mm. long (on either side) 

 in line transversely, in front of plate ; a rather larger one in line with these 



