IV -NOTES ON ENTOZOA OF MARINE FISHES OF NEW ENG- 

 LAND, WITH DESCRIPTIONS OF SEVERAL NEW SPECIES. 



By Edwin Linton. 



In the summers of 18S4-'85 I collected Entozoa from several of the 

 commoner species of food-fishes and Selachians at the summer station 

 of the U. S. Fish Commission, Wood's Holl, Mass. 



Cestoid entozoa in the adult or strobile condition were found in great 

 numbers in the alimentary tracts of all the Selachians examined. En- 

 cysted forms of the Cesloklca are for the most part confined to the 

 Tcleostei and are found in greatest abundance in the submucous coat 

 of the stomach and intestine, although not infrequently met with in 

 the peritoneum, liver, spleen, ovaries, &c. In every specimen of such 

 fishes, as the Bluefish (Pomatomus saltatrix), Squeteague (Cynoscion 

 regale). Striped Bass (Roccus lineatus), &c, examined, the walls of the 

 alimentary tract were spotted thickly with minute cysts, which, when 

 opened, were found to contain larvae of some Cestods, most of them of 

 the genus Ehynchoboihrium. Some from the submucous coat of the 

 Squeteague (C. regale) seem to be larvae of the species which I have 

 named E. bisulcatum. 



In the gall-bladder of nearly every specimen of Squeteague (Cynoscion 

 regale) that I have examined, I found hundreds of larval Tetrabothria. 

 Tliey are usually attached to the walls of the cystic duct in clusters of 

 such size as to obstruct the passage. (Plate VI, Figs. 6 and 7.) They 

 are easily dislodged and often may be seen in vast numbers in the amber- 

 colored contents of the gall-bladder. These larvae, when placed in sea- 

 water, are quite active. Each moves by alternately thrusting forward a 

 pair of bothria and by alternate contraction and extension of the body. 

 While this is in progress the body is constantly changing its form. At 

 times it is long and filiform, at others short and broad. At rest it is 

 commonly thickened or obtuse in front, tapering posteriorly. The body 

 of the larva consists of a thin limiting membrane about 0.05" 11 ' 1 thick, 

 inside of which is a granular parenchyma, the latter a clear fluid filled 

 with highly refractile globular masses averaging 0.01 mm in diameter. 

 The bothria are four in number, without hooks, and in the majority of 

 those examined, without costa?. In some specimens there seems to be 

 the beginning of an auxiliary acetabulum at the apex of each bothrium. 

 [l] 453 



