REPORT ON THE AQUATIC HEMIPTERA 
Collected by the Barbados-Antigua Expedition 
from the University of Iowa in 1918 
J. R. DE LA TorRE-BUENO, F. E. S. 
White Plains, N. Y. 
There is before me a very interesting small collection of wa- 
ter-bugs, the fruit of the University of Iowa expedition in 1918. 
This little lot, as always in aquatic Hemiptera from little-known 
places, is extremely puzzling, because, while all the forms are 
well-marked, there is no certainty but what there is one, or more, 
undescribed species present. This can be decided positively 
only by a monographic study of genera, for which material in 
the aquatic forms is, alas, but too scanty. In this collection 
there are long series of two forms only—Arctocorisa antiguensis 
n. sp., and Gerris (Iimnogonus) guerim L. & S. (marginatus 
Guér.). There are also several each of Buenoa albida Fieb. and 
Pelocoris femoratus P. B. The others are only in ones and 
twos and appropriate comment (or protest) is made where it 
seems called for. 
The order of the families here set forth is that of ‘‘A Cata- 
logue of the Aquatic and Semiaquatic Hemiptera’’ by Kirkaldy 
and Bueno, in Proceedings of the Entomological Society of 
Washington, XI, pp. 173-215. It is unnecessary to repeat here 
in detail the arguments for this arrangement and establish why 
the order in Van Duzee’s Catalogue has not been followed for 
these families. Protracted study over a long period of years, 
adequacy of material, and acquaintance with the immature 
stages and familiarity with life-histories have led me to this 
arrangement as the more philosophical and that which repre- 
sents most nearly, according to the present state of our knowl- 
edge, the phylogenetic affinities of these families. The true 
waterbugs form an unbroken series starting with the Acan- 
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