Notes on the genus.Microcotyle. "3 
sharply bent so as to form teeth which give the sucker a better 
hold. In the anterior lip there are three clumps of cell-like palely 
stained bodies probably representing sense organs. 
The neck is long and graceful. The genital cloaca is oval with 
. a small round anterior opening. The short triangular spines, of 
which there are a great many, seem to be distributed pretty evenly 
over the outside of this sac-like structure but are largest and most 
closely placed about the orifice. Evidently it is a somewhat ever- 
sible sac. Behind it there is seen an olive shaped mass which is 
the termination of the rather muscular vas deferens and which must 
therefore represent the eirrus. It is flanked on either side by a 
group of about fifteen spines and in front of it there is apparently 
a separate opening. 
The ovary is placed more or less across the middle of the worm 
and is not very large. T'he oviduct can be plainly seen to be joined 
by the neck of the seminal reservoir which lies posterior to it on 
the left side of the worm, and by the vitelline duct after which it 
passes into the shell gland and the uterus. The eggs occur in small 
number, usually one or two only, and are provided with rather short 
stout prolongations at each end. There is no long finely coiled 
filament as in some other forms. 
There are thirty-two rather large testes from which the some- 
what thickwalled vas deferens runs forward. 
Measurements. 
Length 6 mm 
Width 0,80 
Sucker disc 2,50 
Number of suckers 120 
Diameter 0,05 
Number of testes 32 
Eggs 0,31 x 0,04 
Anterior filament 0,24 
Posterior filament 0,07 
U. S. Fish Commission. Woods Hole. 
M. pomocanthi n. sp. 
In describing M. angelichthys in a previous paper it was stated 
that in its structure that worm resembled in many points others to 
6* 
