74 THE entomologist's nECORD. 



each shows as a dull orange-coloured cup-shaped hollow, with a 

 darker (brownish) rim. Just above the spiracles, a sub-spiracular line 

 is to be traced slightly paler than the ground-colour. Under a high 

 power (one-sixth) this line is found to be studded with minute 

 glandular-looking warts, probably the traces of supra-spiracular 

 tubercles, a few similar warts occupy the position of the pre-spiracular 

 tubercles, but they are all quite smooth, and bear no hairs, although 

 the skin is plentifully supplied, both laterally and dorsally, with short 

 brown hairs. These are particularly abundant on the hinder 

 abdominal segments, and on the posterior edge of the anal segment 

 the black hairs are much longer than elsewhere, and form a dense 

 fringe, which is even visible to the naked eye. 



Mode of walking, prolegs, etc. — The slow gliding motion of the 

 larva is very remarkable. The anal prolegs are pushed forward as far 

 as possible ; and this forward movement is followed by each pair of 

 prolegs in turn, and then by the true legs, so that a wave seems to 

 run from segment to segment along the body. When at rest, the legs 

 are retracted, and the larva rests almost flat upon the surface of a 

 leaf. When in motion, the anal segment is slightly raised. The pro- 

 legs are retractile, exceedingly pale, and terminated by a broad flange 

 covered Avith short, and apparently weak, pale brownish hooks. The 

 joints of the prolegs are supplied with long pale glassy-looking hairs, 

 like the true legs. The movements of the larva give some variation 

 to its tint, for, whilst the larva at rest is very uniformly green, in 

 motion there is a distinctly darker green medio-dorsal line traceable 

 from the head to the anus, making the central furrow look darker than 

 the ground-colour, but this darkening is largely due to the food in the 

 alimentary canal. 



This description was taken on the morning of May 30th. The 

 larva assumed the quiescent form during the evening of the same 

 day, and by the following day had spun a silken pad and girth, and 

 was ready for pupation. 



II. — Larva of Thecla pruni in the quiescent stage preceding 

 pupation. — On May 26th, I received from Mr. H. Mousley a larva of 

 Thecla pruni which had already attached itself to a leaf of blackthorn 

 by a white silken anal pad and slender white girth, that passed round 

 the centre of the post-thoracic segment. The head was quite retracted, 

 and the dorsum had assumed an arched appearance, although the 

 venter was closely appressed to the leaf to which it was fastened. The 

 larva in this position gradually increases in height and width from 

 the pro-thorax to the 3rd abdominal segment, and then narrows again 

 to the anal segment. The 2nd, 3rd, 4th, ,5th and 6th abdominal seg- 

 ments bear a double longitudinal serrated ridge, in the form of a 

 series of raised points on either side of the medio-dorsal area, which 

 forms a furrow between the two ridges. This furrow narrows pos- 

 teriorly, and ends in a point on the anal segment. The absence of the 

 ridge on the thoracic and first abdominal segments makes the dorsum 

 slope rapidly from the 1st abdominal segment to the head. 



The colour of the larva at this stage is yellowish -green, the apices 

 of the ridge-points purplish-red, externally edged with yellowish, the 

 central furrow rather darker green than the ground-colour. The skin 

 is thickly sprinkled with short black bristles, these are mixed with 

 longer brownish hairs on the thoracic segments, with longer white hairs 



