1J:2 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 



The life-history of this very interesting species is still not well 

 known. The larva lives in gravel or sand along the banks of 

 streams. On April 26, 1914, some gravel from the banks of Cas- 

 cadilla Creek, Ithaca, N. Y., was examined near the place where 

 the pupal skins were found in 1913 (see later). No signs of larvcc 

 or pupcE were discovered after a close search. On May 6, the same 

 bank was examined and some ten larvae and seventy-five pupee were 

 found. They occurred in the gravel that was thickly penetrated by 

 grass-roots and rhizomes; pure gravel was nearly destitute of these 

 insects. Associates of these larvae and pupae at this time were Pae- 

 dcriis Jittorariiis, Laccobius ag'dis, many larvae and pupae of Tab- 

 auidac and a few Eriopteriue crane-fly larvae. Some of the larvae 

 pupated during the night while in water contained in a flat porcelain 

 dish. The above data seems to indicate that the larval existence is 

 spent in or under the water of the stream and the larva comes to 

 live in the sand along the edge of the stream only when fully grown 

 and ready to pupate. 



The pupa occurs in the sand as described above, usually in com- 

 pany with the larvae of the species and various associates. The fol- 

 lowing data is taken from my field notes, May 2, 1913 : Two fully 

 grown pupae and several cast pupal skins were found on a pebbly 

 beach along Cascadilla Creek. They were much rarer than the 

 adult flies of two years ago and the number of cast skins per square 

 foot for any place was only three or four, nothing like the numbers 

 found in the related Enocera longiconiis Walker. May 3, 1913. 

 One pupa found on a pebbly beach along the Inlet (Ithaca) by J. C. 

 Faure. It was in the loose sand with such natural associates as the 

 following: larvae and pupae of the deer-fly, Chrysops excitans, and 

 many adult beetles, Cicindela sexgiittata, and C. vulgaris, common; 

 Elaphriis riiscarius, a few; Tachys, sp., several; Omophron, sp., 

 Dyschirhis sphaericollis, Agonoderus partiarhis, Anisodactylus dis- 

 coideus, Cryptobium bicolor, Paederiis Iittorarins, Bledius, sp., etc. 

 The pupa of Hexatoma occurred in the same stratum as the adults 

 of Omophron. 



The adult insects fly during May and June and may be swept from 

 rich vegetation near the streams from which their larvae emerged. 



