NOTES TOWARDS A LIFE-HISTORY OF THESTOR BALLUS. 255 



ence, to suit them admirably, no deaths occurring except by accident 

 and to preserve specimens. The following notes were taken from 

 time to time, and as, probably, notwithstanding their incoherence and 

 repetitions, they will be more descriptive of the progress and appearance 

 of the larvi^ than if I were now to edit them, I present them as origin- 

 ally written. All the photographs are by Mr. Tonge from the actual 

 specimens, and the diagrams are copied from my rough notes. 



Larva. — First instar (From a larva, well-grown in this stage, pre- 

 served in formalin ; pi. xii., figs. 1-2): — Structure well-shown, colour, of 

 course, doubtful, a somewhat ochreous-yellow, with head, first thoracic 

 plate, hairs, legs, and proleg crochets, black, the hairs, however, pale at 

 tips. Length l'6mm., thickness 0-3mm., longest hairs about O'Smm., 

 hairs spiculated, general surface closely beset with darker points, appar- 

 ently finely spiculate. The abdominal segments have, on either side, three 

 dorsal hairs, and of these the front one is about a fourth the length of 

 either of the others; these are on the same zone of the segment, 

 one a little nearer the middle line, the other further out than the 

 front one. At an interval below are two hairs about half the 

 length of the dorsal ones, these are nearer to the spiracle than to 

 the dorsal group ; they are nearly as far apart as the lower one is 

 from the spiracle, the upper one is in about the same zone as the 

 spiracle, the lower one distinctly behind. Immediately below the 

 spiracle is a group of three long hairs, very close together, one is 

 immediately below the spiracle, the other two behind, one rather above 

 and the other below the first. A little below and behind these three is 

 another rather long hair, it is, indeed, very close to them, and tempts 

 one to describe it as of the same group, its chief distinction is that the 

 three hairs keep together outwards and rather upwards, this one keeps 

 itself separate from them and inclines backwards. Below these again, at 

 some distance, there are, on abdominal segments 3, 4, 5 and 6, halfway 

 between these four and the prolegs, two shorter hairs at the same level, 

 one pointing forwards, the other backwards. On 1, 2, 7 and 8, only 

 one central hair occurs in this position. They, however, possess ventral 

 hairs (in place of prolegs). Immediately above these and between them 

 (on 3, 4, 5, and 6) is a large conspicuous lenticle, another lenticle is 

 conspicuous between the dorsal and supraspiracular groups of hairs. 

 This one occurs also on the 2nd and 3rd thoracic. The thoracic plate is 

 simple, straight i^ehind, rounded to the ends in front, each side with three 

 hairs and a lenticle in front towards the outer end. The first spiracle 

 is quite at back of segment, a little higher than it, and in the middle 

 of the segment is a large lenticle (more like a spiracle than the spiracle 

 itself), between it and the plate are three long hairs, tolerably in line 

 from back to front, another in front of it, and a fiftli immediately below 

 it. Two stouter hairs are some way below, toward legs, and are repeated 

 on the following segments, looking identical with the similar hairs 

 above prolegs. On the 2nd and 3rd thoracic segments the three dorsal 

 hairs are the same as on the abdominal, viz., two long and one short on 

 either side. Below these are five hairs representing the circum-spira- 

 cular groups (lii, iv, and v ?) of the abdominal segments, of these, four 

 are in a transverse line a little behind the middle of the segment, and 

 one a little in front between the two upper ones. On the 8th and 9th 

 abdominal segments there is a little difference in the arrangement of 

 the dorsal hairs, not determinable in specimens. The anal plate 



