1897.] Zoology. | 347 
In the Periplanete and Blatte the tubes are grouped into six bundles, 
each with 15-20 tubes, opening at the summit of a very short conical 
tubercle. These six tubercles are simple evaginations of the intestinal 
wall, and are disposed in a circle about the intestine, at almost equal 
distances from one another. In Polyzosteria the tubes are filamentous, 
short, and likewise grouped into six bundles. In Blabera the mode of 
opening is characteristic, and very different from that in the rest of the 
Blattide. The tubes to the number of 50-60 are plain, embracing 
about a third of the intestinal circumference. 
In the Acridide the number of tubes is very variable. Certain 
species (Pecilocerus and Pyrgomorpha) have as many as a hundred, 
others (Pamphagus) have 60-70, others (Gdopoda) 70-80, others 
(Psophus, Pachtylus, ete.) 50-60. In all the tubes are grouped into 
a few bundles (5-6). 
In the Locustide the number of tubes exceeds 100, grouped into six 
bundles, opening at the summit of 6 cylindro-conical tubercles, disposed 
sometimes regularly at equal distances fram one another, sometimes 
irregularly, at the origin of the hind gut (Locusta, Decticus, Salomona, 
Pseudorhynchus, Platicleis, etc.). In the Ephippigerine one meets with 
three or four of these tubercles and some 110-120 urinary tubes. 
Finally, in Gryllacris, which in general have but a single, short collect- 
ing tubercle, there are some 80-100 Malpighian tubes. 
In the Gryllide the number of tubes is great, and exceeds a hundred. 
In Gryllus and Gryllotalpa one finds 100-120. They open into a long 
unpaired cylindrical collecting tubule (ureter). This, after a course of 
9 mm. to 12 mm., opens at the summit of a conical tubercle furnished 
with four valves limiting an gqsteriated orifice ( Gryllotalpa). 
Eels Feeding on the Eggs of Limulus.—In the latter part 
of May, four or five years ago, while walking at dusk along the Kicke- 
muit River, which flows between the town of Warren and Bristol, R. I., 
I noticed many horse-feet crawling on the sandy bottom of the river. 
The tide was high, and they had come in from outside, as is their habit 
at high water. What attracted my attention the most was the fact that, 
as they lay there on the river bottom, many eels had worked their way 
into the clefts between their heads and abdominal regions, and were 
apparently feeding. Some of the eels were very large, and made a 
strange sight with their heads under the shell and their tails sticking 
out sideways. Sumetimes two or three were under one horse-foot, and 
if I had had an eel spear I could have caught a good mess. I have 
since wondered what the eels were eating. Sometimes I think it might 
