90 Bulletin of the Brooklyn Entomological Society Vol. XV 



Orders in part amphibious : 



Coleoptera : Parnidse, Haliplidse, Gyrinidse, Hydrophilidse, 

 Dytiscidse, Galerucinas, etc. 



Diptera : Psychodidse, Corethridse, Chironomidse, Culicidse, 



Stratiomyidee, Tipulidse, Simuliidse, Dixiidse, in part or 



wholly, etc. " ' 



Hemiptera : Corixidas, Belostomatidse, Naucorid?e, Notonectidse, 



etc. 



Hymenoptera : some parasites (some Trichogrammatidse, etc.). 



Lepidoptera : Nymphalinse, some Noctuid genera. 



Megaloptera: Sialidse, Corydalis. 



Neuroptera : Hemerobidas. 



It should be noted that the amphibious habit is not confined to 

 a few orders, but that it may occur anywhere. It may be that the 

 entire family leads an amphibious life, or that a single genus of a 

 family is amphibious. Thus, among the Ceratopogonidse, one 

 section is completely terrestrial in habit, while the remainder is 

 amphibious ; among the Chrysomelidse, the subfamily Galerucinse 

 is aquatic, the remainder terrestrial. Again, among aquatic Cole- 

 optera we find nearly uniformly that the adults also are am- 

 phibious, while in all other orders the adults spend their lives 

 above water, although a number of genera are known in which 

 the adult enters the water for prolonged period for oviposition 

 {Enallagma and Aeschna among Odonata, many Trichoptera, 

 especialy micro-Trichoptera, for periods from one half to six 

 hours). 



Two terms used frequently in this paper will need definition: 

 surf ace -breathers and water-breathers. By surface-breathers 

 such animals are designated as come to the surface of the water 

 to renew their oxygen, — that is, they breathe atmospheric air. 

 Water-breathers are all animals that obtain their oxygen in solu- 

 tion directly from the water. The dividing line between these 

 two categories cannot be as sharply drawn as one might suppose, 

 for the degree of aquaticity is variable. For instance, as will be 

 shown later, surface-breathers may become temporary water- 

 breathers. 



Among water-breathers two types of breathing exist : an inter- 

 nal oxygenation, i.e., the oxygen exchange takes place within the 



