March, igi-.] WiLLIAMS : NORTH AMERICAN LaMPYRID.E. 29 



this vicinity to furnish even a little of the food. The larv?e would 

 not touch living slugs in the laboratory, but earthworms, particularly 

 those which had been wounded, were often attacked and eaten. A 

 good-sized earthworm was placed in a jar with several larvx. In 

 the bright electric light but one was bold enough to affix itself to the 

 hinder part of the worm, with its prothorax bent down towards its 

 prey. It allowed the worm to pull it about, and let drag its expanded 

 prolegs, chewing steadily and relentlessly the while. Apparently the 

 worm suffered partial paralysis in the attacked region since it retali- 

 ated but feebly, except at the first few tweaks. In the morning the 

 worm was found dead, with several larva; feeding upon it. One end 

 was quite eaten away, and here and there along its remaining length 

 was a number of lumps which were evidently the result of bites. 

 Another worm in the same dish remained uninjured. A decidedly 

 large and vigorous worm, about four inches in length, was left over 

 night in a battery jar half filled with earth and containing about 

 thirty large larvx. One end of the creature had been previously in- 

 jured but the animal was nevertheless quite active. At lo P. M., 

 upon examining the jar after it had been kept in darkness for some 

 time, it was found that the worm had been attacked and was being 

 devoured at three different points, including the wounded end. I 

 counted fifteen larvae engaged at this repast. The worm was still 

 capable of slow movement, and, if squeezed with a pair of forceps, of 

 considerable activity. The next morning revealed a number of much 

 distended larvae, feeding on the remnants of their prey — two pieces, 

 one a mere stub, the other a somewhat flaccid piece an inch and a 

 quarter in length. It is quite probable that while earthworms form 

 a good proportion of the food of Photuris, it must feed upon a diver- 

 sity of other forms. The mandibles seem to be blunter and much 

 stouter than those of most lampyrid larvae so that the creature may 

 devour what it can overcome. Not being provided with salivary 

 glands, it must, like many other carnivorous beetle larvae (Carabidae, 

 Dystiscidse, etc.), inject an alimentary poison, probably secreted by 

 the midgut, into its prey. 



Unlike the more slender Photinus, the Photuris larva is hardly 

 subterranean in its nocturnal habits and is doubtless a more extensive 

 traveller. By the end of October, I could find but few larvae in the 

 field. The ones confined indoors were for the most part resting 



