90. Dr. R. Kossman on the Entoniscide. 
to the combination of Sacculina and Entoniscus, as also with 
regard to the sea of the host of the latter. I find both to be 
inadmissible. In opposition to the supposed frequency of the 
association of the two parasites, we have the fact that, of my 
very numerous examples of Hntoniscus, only one was asso- 
ciated with a Sacculina; probably the above-mentioned natu- 
ralists have accidentally fished in a spot where both epidemics 
prevailed at the same time. But if Fraisse actually supposes 
that at Naples Entoniscus occurs solely, or almost solely, upon 
females, this is plainly controverted by the fact that among 
the first 198 Pachygrapst that I had opened, and of which 75, 
or two fifths, were females, I found eight males and only two 
females attacked by Hntoniscus. I can confirm the sterility 
of the females. 
I now pass to the discussion of the internal anatomy. With 
regard to this a good deal has been done before me; but in 
this also several considerable mistakes have been made. On 
the internal structure of the male, Fraisse and Giard, as they 
have never met with it, could say nothing; but-what Fritz 
Miiller (1, p. 14) states aboutit is correct and almost exhaus- 
tive; it is sufficient to add that the nervous system and the 
histological structure of the organs agree with the characters 
of the male Bopyridee as completely as all the rest. I have 
not thought it necessary to give figures, as I can refer to those 
which I have published of the male of Gyge (“ Studien iiber 
Bopyriden, IJ.,” Zeitschr. fiir wiss. Zool. Bd. xxxvi. pl. xxxv. 
figs. 3 & 5). a 
As to the internal structure cf the female of Entoniscus 
Fritz Miller has less to say, as above cited. He speaks of 
“ conical ceca” which are to be found in the head, meaning 
thereby the papille, subsequently quite correctly represented 
by Fraisse and Giard, which are attached, not, as he seems to 
suppose, to the outer, but to the inner surface of the stomach ; 
otherwise he has nothing to say about the earlier portion otf 
the intestine. Of the liver he correctly states that it consists 
of two tubes placed close together on the ventral surface, and 
extending from the head as far as the neighbourhood of the 
abdomen. On the connexion of the liver with the: intestine 
and the further course of the latter he says nothing. He also 
states that the ovaries are situated in the back and commence 
a little behind the head, and, further, that they cause several 
protuberances on the back ; but he did not detect their orifices. 
He demonstrates the position of the heart in the pleon. 
The position of the mouth is shown in my figure ; and I have 
also represented its form (Pl. [X. fig. 7) reconstructed from 
longitudinal sections, and therefore perhaps a little distorted ; 
