, 
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 Corixide. 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 (Pl. X XIX, 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 thesis 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 
