1884.) Anatomy and Physiology of the Family Nepide. 253 
ning of the stomach (Fig. 3) and another at the end not so well 
marked, but in neither case are they distinctly separate from the 
rest of the stomach. 
The stomach, taken as a whole, is of unusual size, and much 
saculated by contraction. In the third abdominal segment its 
pyloric end opens into the intestine. Both stomach and intestine 
consist of at least two coats, an external muscular coat and an 
internal mucous coat. The existence of a third coat in the Hem- 
iptera is a disputed point; though Dr. Leidy mentions it in Bel- 
ostoma, and I have found it, to the best of my belief, in Ranatra. 
The muscular coat consists of both longitudinal and annular 
fibers, the former predominating. The peristaltic contractions of 
the alimentary canal are due to these muscular layers, and in the 
insects under consideration these movements are very energetic 
and thorough, separating the liquid food into chyle and excre- 
menta. The mucous layer extends the entire length of the ali- 
mentary canal, and is most easily observed at the pharynx and at 
anus. 
Before emptying into the caecum, the intestine is divided into an 
anterior and posterior portion by a bulbous enlargement, upon 
which the Malpighian tubules are situated. The first part may be 
conveniently called the duodenum, as some authors call it, and 
the after part the ilium. The duodenum is convoluted upon it- 
self several times. In Belostoma it turns from its origin, first to 
the left, then upward, running along the left side of the stomach 
to about one-third its length, then turning upon itself, returns to 
the median line of the body; from this point it passes upward on 
the right side of the stomach, turns with an irregular loop and 
teaches again the median line, where it enlarges into the bulb, The 
Ussues of the duodenum are the same as those of the stomach. 
_ The ilium is slightly larger than the duodenum and coils upon 
self five or six times in a sigmoid manner. In the greater num- 
der of Specimens dissected, the coils were six in number. The 
, ilium empties into a cylinder larger than itself, which represents 
the colon or rectum. The upper portion, which is separated from 
l Ss lower by a slight constriction, is sometimes considered as 
(“Presenting the colon, and the lower portion the rectum. This 
“er diminishes rapidly, and ends in a pointed opening at the 
| a aperture, which is situated above and behind the genital 
