SEA-FISHERIES LABORATORY. 107 
known. But it appears to me that confusion has beer 
created by disregarding differences which, in other groups 
of animals would be of generic value at least; and 
straining the diagnoses of the genera so as to admit species 
which ought to be grouped in some other manner. 
(2) KorLirkertra FILICcOLLE (RupoipHt). (Text fig. 5.) 
Karly in 1910 a specimen of Brama raw was 
obtained from the Menai Straits, and came into the 
possession of Professor P. J. White. This is the only 
record of the occurrence of Ray’s Bream in the Irish Sea, 
though F. Day speaks of its eapture in the Bristol Channel. 
It is a form more characteristic of the Mediterranean and 
Bay of Biscay than of our waters, though it also occurs as 
far north as the Faeroe Islands, a part of the sea with, 
probably, greater faunistic similarity to that of the 
Biscayan area than the Irish Sea, because of the intensity 
of the Gulf Stream Drift. The fish referred to was 
examined by Professor White, who then noticed some 
cysts on the branchial arches, and sent parts of the latter 
to my colleague, Mr. A. Scott. Finally, they were handed 
over to me. 
The cysts contain the interesting Distomid originally 
called D. filicolle, then D. okenw, and now Koellikeria 
filicolle. It is well figured by P. J. van Beneden,* but I 
give a figure here. There were three cysts on the piece of 
gill arch sent to me, but one had been removed. These 
structures vary from about 25 to 12 mm. in greatest 
diameter. The larger cyst contains more than one pair of 
worms. Fig. 5 represents one of the females dissected 
out from the cyst: the head and anterior part of the body 
are filiform, but the posterior part is enlarged and kidney 
* In the ‘“ Mémoire sur les Vers Intestinaux,” Pl. X. 
