38 THE CANADIAN ENTOMOLOGIST. 



as long as the body, reddish; metathorax as in the preceding species^ 

 Length 6 lines. % . Much slenderer than 5 , with lateral margin of face, 

 scape of antennae beneath, and tegulas, pale ; antennae entirely black j posterior 

 tibise dusky, their tarsi pale; abdomen petiolated, long, thickened toward 

 apex. Length 5^ lines. 



^«5.— Ottawa, C. W. (Billings). Coll. Am. Ent. Soc. 



LUMINOUS LARV^. 



We have received the following note from Baron Osten Sacken, of New 

 York, on the subject of our larva : — 



''A luminous larva is mentioned in your No. 4, p. 30. Is it not the larva 

 0Ï Melanactes, described and figured by me in the Pro. Ent. Society, Phil. 

 1862, p. 125, Tab. i. fig. 8, under the name of ' Unknown larvae V 



'' At that time I was uncertain about the genus of the larvae, as well as 

 about the fact of their being luminous. But in a notice which was published 

 in the same proceedings subsequently I communicate the fact, that I found 

 the same larva alive, that it is luminous, and that it probably belongs to the 

 genus Melanactes. 



"The latter article I cannot refer to now, as I have not the book at hand. 

 But it may be found in the Proc. Ent. Soc. Phil., in one of the years after 

 1862, in the form of a letter read at one of the meetings of the Society. 



" R, Osten Sacken." 



The notice referred to we have found in the Pro. Ent. Soc. Phil., Vol. iv. 

 No. 2, in the minutes of a meeting of the Society held on April 10, 1865 

 (p. 8). The Baron, after referring to his paper and figure in 1862. states 

 that, "Last September Mr. J. Carson Brevoort was fortunate enough to find 

 one of the large larvae near "West Point, N. Y., under a stone. The specimen 

 is three inches long, and belongs to the same species as that which I had 

 figured. In the dark, this larva emits a soft green light, shining principally 

 through the sides of the body and the venter ; on the back it appears only in 

 the intervals between the horny segments. The whole length of the larva 

 being thus illuminated in the dark, when it moves briskly about, it is a most 

 beautiful object. The larva is still alive, although I have little hopes that it 

 will undergo its transformation in captivity. But I have not the slightest 

 doubt now that it belongs to Melanactes, the more so as this genus, in Dr. 

 LeConte's arrangement, is placed in the same subtribe (^Cori/mhitini') with 

 Pt/rophorus. At the time when I first described this larva, all the large 

 specimens which I possessed came from the South (Arizona, New Mexico? 

 Louisiana), and I was not aware that such specimens could be found in the 

 Middle States, and as the largest Melanactes occurs in the latter States, this 

 made me doubt that the larva could belong to that genus. The discovery of 



