DESCRIPTION OF A LUMINOUS LARVA FOUND 
NEAR HOLBROOK, ARIZONA. 
BY C. H. TYLER TOWNSEND. 
On the night of June 27, 1892, while camped about five 
miles west of Holbrook, Arizona, I found a luminous larva run- 
ning over the ground. The prothoracic segment was especially 
and continuously luminous, while the other segments, especially 
the more terminal ones, were all more or less so. Each segment 
was luminous for a certain space about the centre of its dorsum, 
and thus taken together they looked like a string of beads in the 
_ dark, the prothorax, however, being wholly luminous. 
The larva is coleopterous. It does not much resemble an 
elaterid larva, while it is equally unlike a lampyrid. It differs in 
its shape, and also very markedly in its characters, from the sup- 
posed larva of melanactes figured by Riley and described by 
Bethune and Osten Sacken.* It further differs very strikingly by 
the luminosity not being located in the same regions of the larva 
as those indicated in the figure above referred to. Instead of 
being at the side of each segment, and at the incisures, the 
centre of the segments is luminous, according to my notes. 
These notes on the luminosity of the larva were made in the field 
at the time, and the details have since escaped my memory. But 
I do not think that I mistook the incisures for the segments. 
Description of larva, Wength, hardly 12 mm.; greatest 
width (segs. 9-10), 134mm. Whitish in color originally; 
changed by immersion in alcohol to a pale rufous above and pale 
flavous below. Elongate, of nearly equal width, but slightly 
narrowed anteriorly, and posteriorly flattened. Consisting of | 
thirteen segments, rather chitinous on whole surface, especially 
on dorsum, head, and ventral thoracic portion. Head retracted 
within the prothoracic segment, the third to twelfth segments 
each retracted for about its anterior one-third within the next 
segment anterior to it. Second or prothoracic segment elongate, 
longer than any of the other segments, gradually narrowed 
* Riley, Amer. Ent., iii, 202; and LeBaron, 4th rep., 99.—Bethune, Can. 
Ent., i, 2.—Osten Sacken and Bethune, Can. Ent., i, 38-9.—Osten Sacken, _ 
Proc. Ent. Soc. Phil., 1862, 125, pl. 1, f. 8; and iv, No. 2, 8. 
