142 THE UNIVERSITY SCIENCE BULLETIN. 
KEY TO GENERA—Concluded: 
B. First (basal segment of the beak longer than the second; 
furrow of the wing membrane nearly or quite straight. (Size 
about 1 inch or less.) Belostoma. 
BB. First segment of the beak shorter than the second. Furrow of 
the wing membrane shallowly S-shaped. (Size more than 1% 
inches. ) 
C. Anterior femora grooved for the reception of the tibiz. 
Lethocerus. 
CC. Anterior femora not grooved for the reception of the 
tibiz. Benacus. 
The keys to species and their descriptions are omitted for the present, 
as the writer is aware that Mr. J. R. de la Torre Bueno has been work- 
ing upon this group for the past few years, and has promised us a paper 
shortly. 
B. BIOLOGY OF THE BELOSTOMATID. 
General Notes. The Belostomids, because of their large size and their 
frequency about electric lights, have been frequently noticed by the lay- 
man. With the installation of electric lights in a town, there usually 
come inquiries regarding these giant bugs. The bugs are sent in with 
the statement that they have never before been in that part of the 
country. On the other hand, they have been there, but have not been 
drawn to the attention of the populace. As an indication of the general 
interest taken in these bugs note the numerous references to be found in 
the American Naturalist of earlier years. This periodical was at one 
time of general interest to all biologists and reflected very well matters 
of general note. 
Another interest that is attached to these insects is the fact that in 
two of the four genera, Belostoma and Abedus, the males carry the eggs 
about with them. 
All of these bugs live in the water, where they rest as a rule, clinging 
to some support with the tip of the abdomen in contact with the surface 
film. All are fiercely predaceous. 
Genus ABEDUS Stal. 
There are five species of this genus listed for America north of 
Mexico, by Van Duzee. A. ovatus, A. breviceps, A. dilatatus, A. macroryx, 
and A. indentatus. This genus is confined to our southwest—Arizona, 
New Mexico, Texas and California. Aside from the collecting habitat 
notes, little has been done on their biology. The eggs are carried upon 
the back as in Belostoma, as evidenced by material in our collections. 
Uhler mentions this fact under his discussion of Serphus in Cambridge 
Natural History. The fierce predaceous tendencies of Abedus macronyx 
have been noted by Harvey under the title, “A Ferocious Water Bug.” 
Here he says that the bug is to be found in the warmer streams and 
ponds of California. Children who wade in these waters have named it 
“toe pincher.”” He placed one in an aquarium and its depredations were 
astonishing. It devoured a 3-inch trout, young frogs, tadpoles, snails, 
and various smaller fry. He then isolated it and found it would devour 
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