4274 Entomological Society. 



ing before, but had escaped before any one could muster up courage to lay hold of it. 

 None of the inhabitants of the village to whom the animal was shown knew anything 

 about it; though it cannot be of particularly rare occurrence in that part of Brazil, 

 because I have heard, from an amateur of Zoology from Sahara, that he had met with 

 it several times in that town. 



" The peculiarity in its luminous property consists in its producing two distinct sorts 

 of light ; for while all the segments of the body, with the exception of the prothorax, 

 are each furnished on the dorsal side with two shining points radiating a greenish light, 

 like that which we see in our glow-worm and similar forms, the whole of the head, ex- 

 cepting the eyes, antenna?, and the parts of the mouth, glows like a live coal, with the 

 most vivid intensity, strikingly contrasting with the greenish luminous dots of the 

 rest of the body. It is not, however, by the colour alone, and the locality of the light, 

 that the animal becomes remarkable, and, so far as I know, unique among insects ; 

 but it appears moreover to be permanent: for, although it alternately diminishes in 

 intensity, being at times scarcely observable by lamp-light, it is at other times quite 

 distinct, nay, occasionally visible at mid-day; yet, during the whole of the twenty-four 

 hours in which the insect continued alive with me, it never once lost its luminosity, and 

 the decided alternations in the intensity were but little appreciable in the dark. Again, 

 the greenish light of the segments contrasts with that which issues from the head, 

 by fading and becoming perfectly imperceptible, and then again reviving, as is seen 

 in the Lampyris ; it frequently vanishes and becomes extinct in some of the segments, 

 while in others it continues bright. It is rarely that the light is extinguished in all 

 the segments simultaneously, and, on the whole, it is more nearly continuous than in 

 the kind of insects just mentioned. The radiation takes place from the dorsal parts 

 of the rings, behind and above the spiracles, without having apparently any absolute 

 connexion with them, for it is seen also in segments wanting the spiracles, that is, in 

 the mesothorax and last abdominal ring. The lucid points are of the size of the head 

 of a small pin, and the light is so intense that it shines through the sides of the abdo- 

 men : when it ceases, no particular appearance is observable at the place whence it 

 issued ; and, unlike the luminous spots on the thorax of the shining Elaters, it is nei- 

 ther sharply defined, nor, in general, remarkable by any peculiar appearance ; and on 

 the larva being put into brandy, the red light was extinguished first, and then the 

 green. 



" I have in vain searched for any notice of such a larva in entomological works ; 

 neither is it mentioned in Ehrenberg's known memoir on the luminosity of the sea, 

 prepared, no doubt, from the most extensive information upon all known phenomena 

 of phosphorescence. I may therefore assume that the peculiar light in question has 

 not hitherto been known to zoologists ; although a short notice, giving the main fea- 

 tures of the phenomenon quite correctly, but unaccompanied by any adequate account 

 of the luminous animal itself, from the pen of F. Azara, appears in his 'Voyage dans 

 l'Amerique Meridionale' (t. i. p. 114), wherein the author reports that at Paraguay he 

 saw ' a worm of nearly two inches in length, the head of which glowed at night like a 

 piece of burning coal, and having besides along the body, on each side, a row of holes 

 resembling eyes, from which a fainter yellowish light emanated.' This accords, in all 

 essential points, so entirely with what I observed myself, that I must consider the lit- 

 tle discrepancy of the holes themselves being luminous, as depending simply on a less 

 attentive examination ; and I am therefore of opinion that there can scarcely be a 



