174 THE UNIVERSITY SCIENCE BULLETIN. 
A. Species over 6 mm. long—concluded. 
C. Head, including the large eyes, nearly as wide as the 
pronotum in the male, a little narrower in the female. 
Body robust; legs stout, interocular space not very nar- 
row behind. Length, 7.5 to 9 mm. 
B. carinata Champ. 
CC. Head, including the large, somewhat flattened eyes, dis- 
e tinctly narrower than the pronotum in both sexes; legs 
rather slender, and, like the greater part of the body, 
pale in color. Length, 6.5mm. 8B. albida Champ. 
BB. Pronotum almost unimpressed, though lateral carine are well 
marked in some males. Length, 6.7-8.1 mm. 
B. margaritacea Bueno. 
AA. Species less than 6 mm. long. 
B. Eyes large and prominent; shape slender. 
B. platycnemis Fieb. 
BB. Eyes large, but not prominent; shape more convex. 
B. elegans Fieb. 
The above table is adapted from Champion and from Bueno to sepa- 
rate the species given in Van Duzee. Kirkaldy evidently did not recog- 
nize either of Champion’s species, for he says of B. albida Champ. 
“Wahrscheinlich mit A. platycnemis identisch” and A. carinatus Champ. 
he makes a synonym of his own B. antigone. The writer has been in- 
terested in providing a means of determining the bugs which he may 
meet in his biological studies. He feels that such guides should have been 
provided by those best acquainted with the groups, but where no keys 
are available he has improvised them from the literature and such ma- 
terial as has been authoritatively identified for him by such workers as 
Bueno, Barber, Gibson, Parshley, etc. If the keys include synonyms and 
‘false statements the reader is referred to Van Duzee’s Catalogue and to 
the descriptive literature. The writer wishes most heartily that there 
were more papers dealing with the taxonomy of the aquatics, such as 
those of Uhler, of Bueno, and of Barber. 
Buenoa carinata Champion. 1901. 
Biologia Centrali Americana, vol. 2, p. 372, 1901. 
“Elongate, robust, smooth, shining; head and pronotum sordid white. 
the color of the latter modified by that of the mesonotum showing 
through; the scutellum usually black in front and rufo-testaceous or 
testaceous behind, sometimes entirely pale; the elytra sordid white, the 
colour modified by that of the metanotum and the apex of the abdomen 
showing through, these parts being usually black and the rest of the 
upper surface rufo-testaceous or testaceous; the under surface, antenne, 
and legs testaceous, the venter black, the terminal segment and some 
San 
spots on the connexivum excepted, the posterior femora beneath, and — ; 
sometimes the anterior and intermediate tibize externally, each with a 
dark streak down the middle. Head (with the large eyes) nearly as 
wide as the pronotum in the male, a little narrower in the female; 
interocular space not quite twice as wide on the vertex’as at the base, 
considerably narrowed beneath, the vertex sulcate down the middle. 
Pronotum about as long as the scutellum in the male, slightly shorter 
