50dj MR. K. TKIMEN ON ASTUAPTOK ILLUMINATOK. 



at Buenos Ayres ; and it was there, about twelve years ago, that 

 he observed the singular larva in question. 



Without communicating to Mr. Ogilvie the contents of Mr. 

 Murray's paper, I wrote to him for such particulars as he might 

 be able to furnish respecting the caterpillar of which he had 

 formerly told me ; and it is by his permission that I convey to 

 the Society the brief note that follows. 



The larva was brought to Mr. Ogilvie by one of his pupils, 

 who had found it in some part of the Montevidian State. It was 

 kept alive for two or three weeks, in the hope that it would 

 assume the pupal condition, but at length died, probably for want 

 of food. Mr. Ogilvie further states : — " As far as I remember, 

 it looked by daylight like an ordinary grub. It was, I thinlc, a 

 little over 2 inches in length, and of a dark brownish colour. 

 "When put to travel across the table iii a dark room, it looked 

 exactly like a miniature railway-train. The head was lit up witli 

 a reddish light, and the tail with a greenish one ; and at the 

 point where each of its legs was joined to the body there was a 

 tiny globe of white light." 



This account so nearly agrees with that given by Mr. Try (as 

 recorded by Mr. Murray), that there can be no doubt of the close 

 alliance, if not species-identity of the insects concerned. The 

 only differences to be noticed are the much larger size of the 

 Montevidean larva, and Mr. Ogilvie's mention of a "greenish" 

 instead of a wJdte light at the tail. As regards the latter cha- 

 racter, it should be observed that Mr. Ogilvie writes from me- 

 mory only ; but my own observations lead me to think that the 

 light emitted by luminous insects, when not seen through any 

 intervening substance, is always of a greenish tinge ; and in tlie 

 case of this larva, the greenish lustre may have been more ap- 

 parent from the contrast with the red light at the head. On the 

 question of size, however, Mr. Ogilvie states, after an inspection 

 of the plate accompanying Mr. Murray's paper, that his speci- 

 men was " certainly larger ;" and, considering Mr. Murray's 

 observations on the probability of Astrapior being the larva of 

 Fyrophorus, the greater size of the Montevidean specimen tends 

 to strengthen his view that this splendidly adorned grub may be 

 the earlier condition of P. noctilucus. 



E. Trimbn. 



