250 American Fisheries Society 



found in several locations, viz., in the vicinity of the first 

 dorsal fin, in front of the caudal fin, near the base of the 

 anal fin and between the pectorals. Usually they lay deep in 

 the muscle tissue near the supporting spines of the fins, 

 though a few were found in the muscles but a little below the 

 skin, and a few near the peritoneal lining of the body cavitv. 

 All were embedded in the muscle tissue. Of the 27 cysts 

 that were found, 19 were in the vicinity of the first dorsal 

 fin, 15 of them lying deep in the muscles and near the sup- 

 porting spines of the fin, 2 near the exterior and 2 near the 

 interior of the body wall; 4 were found deep in the muscles 

 in front of the caudal fin, 2 were near the pectoral fins, 

 and 2 near the supporting spines of the anal fin. In all 

 cases the cysts were thin walled, so much so indeed that 

 the distomes usually liberated themselves by their own ex- 

 ertions when the cysts were placed in water. 



The distomes vary in size and are remarkably contrac- 

 tile. One of the larger specimens when removed from its 

 cyst and placed in water was very active and varied in 

 length from 3 to 10 millimeters. The neck in particular was 

 very contractile, shortening until it was but a nodule and 

 lengthening until it was slender and thread-like. The body 

 was fiat and leaf-like and the intestines were salmon color. 

 In a lot of these distomes mounted in balsam the smallest 

 is 3 [ j millimeters long, 1 millimeter broad, and the largest 

 is 7 "' j millimeters long and 2 millimeters broad. In all 

 cases, whatever the size, these distomes showed about the 

 same stage of development, which was sufficiently far ad- 

 vanced to admit of specific determination, so that one can 

 confidently refer them to the species found adult in the 

 mouth and pharynx of the heron and the bittern. 



Prof. R. Ramsay Wright, in 1877, reported a distome 

 from the bittern (Botanus minor). The worms were found 

 in the mouth at the sides of and below the tongue. Mac- 

 Callum, in 1897, reported the same worm under a different 

 name from the heron (Ardea herodias). Roth of these 

 hosts were obtained in Canada. Osborn in this current year 



