1883.] Notes on the Chetonotus larus. 1219 
cesophagus is surrounded by a thick, dense, muscular tissue of 
circular fibers, and the intestine is surrounded by a layer of large 
nucleated cells, outside of which is another layer of much smaller 
ones which are more difficult to make out. 
Directly above the cesophagus is a globular body or cavity, but 
I cannot conjecture what its functions are. 
In the median line, above the intestine, is situated the ovary, in 
which is developed but one egg at a time. This egg is very large 
as compared with the size of the animal itself. The nucleus is 
plainly visible even before the discharge of the egg from the 
ovary. The oviduct is easily traced to the outlet immediately 
above the anus. 
I have often seen this animal discharge its egg, which, although 
it is of such a large size, does not seem to cause it any inconve- 
nience whatever. When one is moving about slowly and feeding 
quietly, all at once it stops, and bending over slightly, with an 
apparent muscular contraction, the egg is discharged, the time 
occupied being not much more than one second, after which the 
Chztonotus instantly returns to feeding as though nothing of 
importance had occurred. I have watched the development of 
the eggs at one time and another, though not continuously, and 
the young when nearly ready to hatch are of the same form and 
structure as the adult, but doubled up within the shell. I have 
also seen all sizés from the egg up to the adult, and although for 
want of assistance I have never been able to trace the entire de- 
velopment of one individual through, yet I have no doubt that 
these animals are never parasitic, and that they do not pass 
through any alternation of generations. 2 
It is exceedingly curious and interesting to see with what 
facility they use the caudal appendages, sticking them to the glass 
Slide or cover in such a manner that, by careful focusing, one can 
see the sucker-like action of the tips of these organs while they 
“way about one way and the other in the water. At the same 
time the bands of cilia on the under side are in constant motion, 
Ag a current of water to pass along by the mouth, carrying 
cir food in Suspension, which they readily secure. Suddenly 
they let go from the slide, and the action of the cilia causes them 
-to move through the water with great rapidity, till they reach 
some new feeding ground, where they again anchor themselves 
and fish for another meal. 
