DESCRIPTION OF A LUMINOUS LARVA FOUND 

 NEAR HOEBROOK, 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 difiers in 

 its shape, and also very markedly in its characters, from the sup- 

 posed larva of ■nielanades figured by Riley and described by 

 Bethune and Osten Sacken.* It further diflfers 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. Length, hardly 12 mm.; greatest 

 width (segs. 9-10), i^ mm. 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. Eut. Soc. Phil., 1862, 125, pi. i, f. 8; and iv. No. 2, 8. 



