hungerford: aquatic hemiptera. 43 



getting the larger plankton of the pond upon which these latter 

 largely feed. 



The predatory equipment of all of the above is perfectly 

 obvious when you study it, but there is one large family of 

 water bugs whose external equipment is strikingly peculiar 

 and whose front legs, if used for catching and holding prey, 

 have developed along a line quite remote from the usual form. 

 This family is the Corixidae. The tarsus of the front leg is 

 flattened, spoon-shaped, and fringed with long hairs. The 

 inner surface of this pala is set with short processes, as seen 

 in the figure (PI. XXIX, fig. 4) . Equipped in this fashion they 

 make admirable scoops for gathering in the flocculent ooze 

 upon which these insects feed. The feeding habits of these 

 insects are elsewhere described in this thesis, and also in a 

 paper that appeared in the Journal of the New York Entomo- 

 logical Society. 



RESPIRATION. 



The respiration of those that tread or row upon the surface 

 is like any terrestrial Heteroptera, and so our consideration can 

 pass directly to the submerged fauna. On this subject there has 

 been much speculation and some morphological study. The 

 writer has not, as yet, had the time to review the question ex- 

 haustively first hand. To arrive at the actual truth it will be 

 necessary to study the structural equipment of each type, and 

 with this foundation, experiment with living material. Of all 

 who have written on the subject, only three have in fact at- 

 tacked the problem correctly. These are Brocher, Hoppe and 

 Ege. Brocher's work covers a wide field. Hoppe devoted an en- 

 tire thesia to "Atmung von Notonecta glauca." His results do 

 not agree with Brocher's, and thus the writer does not care to 

 become a third party to the discussions until he has satisfied 

 himself completely. The old idea was that insects carried a 

 store of air below with them. Brocher, however, after remov- 

 ing the guard hairs and modifying the air reservoir equipment 

 in various ways, concludes that most of the air enveloping a 

 submerged insect is expired air! After dedicating a whole 

 series of papers to the records of the prosecution of this phase 

 of the biology of aquatic insects one must consider very ser- 

 iously his conclusions. The most recent paper on the subject is 

 by Bueno, and appeared in the Annals of Entomological Society 

 of America for December, 1916. Unfortunately this writer 



