SOME POINTS IN THE ANATOMY OF RANANTRA 
FUSCA P. BEAUV. 
WM. S. MARSHALL AND HENRY SEVERIN. 
Although the anatomy of Ranantra has already been described 
by Dufour (2) and by Locy (5) it appeared to ns, after work¬ 
ing for some time on this Hem ip ter on, that a further contribu¬ 
tion could well be made, correcting some statements of these two 
workers, and on some points extending their observations. The 
specimens used were R. fusca and were all obtained near and in 
the city of Madison. They were all collected late in the autumn 
or early in the winter, the winter collecting requiring much 
time, it being found that at this time of the year R (mantra 
buries itself in the mud at the bottom of pools or creeks. The 
specimens were prepared by injecting alcohol into! them, a hypo¬ 
dermic syringe being used, or cutting the body open before 
throwing them into the preserving fluid. With a few specimens 
a nearly saturated aqueous solution of corrosive sublimate was 
used which was well washed out before finally placing them in 
alcohol. 
Alimentary Tract .—(PI. XXXIV, Figs. 1 and 2.) The 
very thin oesophagus extends straight through the head and 
entire thorax, the diameter remaining the same throughout its 
entire length. At the posterior end of the metathorax there is 
a rather abrupt enlargement which marks the end of thel oeso¬ 
phagus and the beginning of the mid-intestine. This second 
division of the alimentary canal is separable 1 into two part's, the 
anterior extending in a straight course through the first three 
abdominal segments, the posterior being entirely within tbe 
fourth segment and longitudinally folded tiwo or three timjes. 
These folds while, in general the same in their arrangement in 
all specimens, yet show quite an amount of individual variation. 
The next division, the ileum, passes through parts of the fourth 
