[17] NOTES ON ENTOZOA OF MARINE FISHES. 735 



ferent from the first specimen. They (lifter also from most descriptions 

 of this species. The segments in question have, however, every appear- 

 ance of being much contracted. Fine transverse lines appear on the 

 faces, while the margins are wrinkled ; the segments themselves are 

 quite thick and stout. A short distance back of the head the segments 

 are alternately shorter and longer, as noted in the first specimen, 

 while toward the posterior end of the body the adult segments are ar- 

 ranged in groups of from four to six simple segments, as if the latter 

 were partially fused together, which is another characteristic of this 

 species. 



The ova have the same dimensions as in the first specimen, and are 

 collected in oval or oblong masses. Here and there a mass occurs 

 whose size far surpasses those of adjoining segments, and which causes 

 the walls of the containing segment to bulge out into a prominent lateral 

 lump. This feature was also observed in the first specimen. 



The external openings of the oviducts are on oue side in the shape 

 of a row of lateral pores along the median line. The reproductive 

 apertures are on the opposite side. Of these, but one, the male, could 

 be certainly made out in the specimen when examined entire in glycer- 

 ine. In nearly every case the cirrus was protruded. It is short, coni- 

 cal, and stands about the middle of the segment on the median line. It 

 was difficult to get exact measurements of the length. The following- 

 dimensions, which were obtained by turning the strobile on edge and 

 measuring the cirrus in outline, are nearly correct : Length, .l" ,ln ; 

 breadth at base, .04 mm ; breadth at apex, .026 ,ULU . When retracted it 

 becomes a very short papillae. Upon examining a few segments in 

 glycerine, with an enlargement of some three hundred diameters, I 

 noticed that there were two ducts leading to the common opening. One 

 of these was continuous with the protruded cirrus. The other led to a 

 point behind the cirrus and at its base. I am inclined to believe from 

 this that both reproductive organs have a common cloacal opening 

 about the middle of the segment and on the median line. If this is 

 the correct view, the vagina is quite small and opens immediately be- 

 hind the cirrus. This differs materially from Van Beneden's figures of 

 this species. 



I have had some hesitation with regard to referring these speci- 

 mens to D. punctatum, principally on account of its small size. 



Drummoud, however, in his u Notices of Irish Entozoa" (Charls- 

 worth's Mag. Vol. II, p. 574) speaks of this worm as follows : 



1 have found it largest in the brett, exceeding even 3 feet in length and as mauy 

 liues in breadth ; in the coitus I have found it 2 lines broad, and from 12 to 18 inches 

 long, but in the turbot, so far as my observation has yet gone, it is seldom more than 

 a line broad, and varies in length from 8 to 18 inches. 



Since the hosts in which my specimens were found are closely related 

 to the turbot of the other side of the Atlantic, it is of interest to note 

 that the size of these Dibothria corresponds, in the main, with that of 

 those which Drummoud has found in the turbot. 



