HUNGERFORD: AQUATIC HEMIPTERA. 211 
distinguishable from the face, the opening to the mouth being on the 
front of the so-called beak. The front tarsi are also peculiar, being 
1-segmented, flattened and fringed with strong bristles. They are spoon- 
shaped, or paleform. The middle legs are long, slender, and end in 
two long claws. The hind legs are flattened and fringed for swimming. 
Historical Review. “Corixa’”’ means bug, and is a fitting name for 
these water bugs, for they have a buggy smell. They have been known 
by this name since Geoffrey, 1762. Borner, 1904, in a study of the mouth 
parts of this group, separated these bugs off as a separate suborder, 
Sandaliorrhyncha. The other suborders he called Auchenorrhycha 
(Homoptera), Heteroptera and Conorrhyncha. Bueno even gives them 
ordinal rank, but Reuter reduces the Sandaliorrhymcha to a series under 
the Heteroptera. 
Key to Genera. Doctor Abbott, of Washington University, has been 
working for several years upon a world monograph of these bugs. He 
expected to complete the systematic part two years ago, but the inter- 
ruptions of the times have kept him from so doing. It is a most difficult 
group, and it is to be hoped he can give the workers a practical means 
to determine their material.* For the present the writer gives a tenta- 
tive key to the genera. He knows of too much synonomy to waste time 
on specific keys to the large genus Arctocorixia, which contains some fifty 
species, for instance. Only the males are keyed out satisfactorily. The 
females look much alike. 
KEY TO GENERA OF CORIXIDA®. 
Males. 
A. Scutellum covered by pronotum only at the anterior margin. Pro- 
notum roundly emarginate behind. Tenagobia Bergroth. 
AA. Scutellum covered (except sometimes at posterior angle) by pro- 
notum. 
B. Strigil absent. Pronotum and tegima more or less rastrate. 
Conspicuous black spot usually present on hind tarsi. 
Callicorixa White. 
BB. Strigil present. 
C. Strigil on left side. Pronotum and tegmina smooth, 
shining, asymmetry on left side. Corixa Geoff. 
CC. Strigil on right side. 
D. Head of male sharply acumiate. Asymmetry right. 
Strigil small. Ramphocorixa Abbott. 
DD. Head of male normal. 
E. Hind wings usually aborted. Palar pegs in 
two series, or one crowded row. 
Palmocorixa Abbott. 
EE. Hind wings normal. Stridulatory palar pegs 
well developed, curved in single row. 
Arctocorixa Wallen. 
* Doctor Abbott has now given up this work, and the writer has the task of completing 
Doctor Abbott’s work. He is permitting the keys to stand for the present as first written. 
