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coed with the history, that this was undoubtedly the young larva oi Rhipiphorus, 

 aud though the idea of such a possibility occurred to me at the time (and, in 

 writing to Prof. "Westwood on the point, I even suggested it), still I did not 

 think it was so, and, not having too much time to spare, I passed it by. I 

 am able, nevertheless, to give a tolerably accurate account of it. It is a little 

 black hexapod, about l-50th of an inch ("5 millim.) in length, and l-120th 

 of an inch in breadth, broadest about the fourth segment, and tapering to a 

 point at the tail ; a triangular head with a pair of three-jointed antenna? nearly 

 as long as the width of the head, with legs very like those of ilfe/oe-larvre ; the 

 tibia; ending in two or three claws, which supported and were obscured by a 

 large transparent pulvillus or sucker of about twice th ir length ; this was 

 marked by faint stria; radiating from the extremity of the tibia, giving it much 

 the aspect of a lobe of a fly's proboscis. Each abdominal segment had a very 

 short lateral spine pointing backwards ; the last segment terminated by a large 

 double sucker similar to those of the legs ; and the little animal frequently stood 

 up on this, and pawed the air with it3 feet, as if in search of some fresh object 

 to lay hold of. This little larva finds a wasp-grub suited to its taste, and makes 

 its way into its interior. I believe, from once or twice finding a trace of a mark 

 there, that it enters about the back of the second or third segment. But I do 

 not know this, nor at what age of the wasp-larva it does so. I have, however, 

 succeeded in finding the larva of Rhipiphorus within that of the wasp, before 

 the latter had spun up. Assuming that the wasp-larva lives six days in its 

 last skin before spinning up, I should guess that the youDgest of these had 

 still two or three days' feeding to do. The Rhipipho7-usla,rv& were but a little 

 way beneath the skin of the back, about the fourth and fifth segments, and in- 

 differently on either side. The smallest of these (Fig. A.) was 1-lGth of an inch 

 in length, and, except its smaller size, was precisely like the larger ones I am 

 about to refer to, having the same head, legs, plates, &c. These were of the same 

 size as those of the larger larva;, the difference in size of the latter being due 

 to the expansion of the intermediate colourless integument. I ought perhaps to 

 add that the nest in which I found these was not examined until twelve hours 

 after I had taken it. It had also been so much blockaded by boys stoning it, 

 that the wasps had not had free access to and from it for some time. 



I next take up the history after the wasp-grub has spun its silken cover- 

 ing. By removing this covering from those most recently spiin up, and ex- 

 tracting the contained wasp-larva; from their cells, the larva of Rhipiphorm 

 may be detected still in the interior of some of them. At the side and in 

 front of the third and fourth segments (head being first) of the wasp-larva, the 

 little grub of Rhipiphorus shines through the skin, being rendered viable by 

 certain black markings on it — this part of the wasp being nearly transparent, 

 and full of fluid bathing the newly forming limbs of the pupa. On extract- 

 ing this larva (Figs. B. C), it bears a general resemblance in size and oxitline 

 to the youngest larva of Rhipiphorus that I had found feeding externally on 

 the wasp-grub, but with the very notable exception of the already-mentioned 



