SS ae — 
1884) Anatomy and Physiology of the Family Nepide. 251 
curved points ; (2) a fine scalpel for general cutting; (3) needles 
mounted in wooden handles are very convenient for separating 
the tissues and removing small portions piecemeal, these ground 
to an edge and sharpened form very fine cutting instruments; 
(4) fine pliers or forceps; (5) a good pocket lens, or better, a dis- 
secting microscope. For all histological work and fine anatomy, 
a good compound microscope which, however, need not cost 
more than $35 or $50, is necessary. 
Habits, etc—The family Nepidz, of the Hemiptera, is repre- 
sented in our waters by four distinct genera, Belostoma, Perthos- 
toma, Nepa and Ranatra. They are of common occurrence in 
the ponds and streams about Ann Arbor, except Nepa, which is 
rarely found. The first three mentioned are flattened and oval in 
outline, while Ranatra is remarkable for its long linear form. 
Belostoma and Perthostoma, the most active forms, have their 
hind legs admirably fitted for swimming. Ranatra and Nepa, to 
correspond with their habits, have their hind legs fitted for crawl- 
ing along the bottom and upon aquatic plants. The fore legs of 
all the genera are raptorial and armed with a terminal claw. In 
Ranatra this fits into a groove in the tibia, as the blade of a knife 
fits into the handle. In the other genera the femur is grooved to 
receive the fore leg, and the trochanter, the terminal claw. The 
prey is seized by these raptorial legs and conveyed to the mouth; 
it is here punctured by the three-jointed beak and the nutriment 
sucked out. Their food consists of the juices of larval insects, 
tadpoles, young fish, gasteropods, etc. In Ranatra and Nepa the 
antenne are three-jointed, in Belostoma and Perthostoma four- 
jointed, and concealed in a vaulted cavity opening below the eyes. 
The adult Belostome are very large, ranging from three to four 
and a half inches in length, and are the brigands of the streams 
inhabit. From their rapacious habits they soon exhaust the 
from one locality, then fly to another during the night. 
attack aquatic forms several times their own size. In an 
aquarium I remember having once seen a large Belostoma kill a 
frog four times its size, despite the fierce struggles of the frog to 
In general appearance Ranatra resemble the “ walking-sticks.” 
body ends posteriorly in two long sete, the grooved 
which, applied together, form a respiratory tube as long as the 
omen. The front legs are very long, and extend straight out 
