78 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



MacCallum on gills. They had evidently come from the stomach. 

 Two, collected July 6, 1925, found adhering to an echinorhynchus, 

 not noticed until after it had been in fresh water ; turgid, with prom- 

 inent ventral sucker and reflected neck. Measurements of distomes 

 from this host agree with those from other hosts. Measurements of 

 one in balsam : Length, 1.08 mm., breadth, 0.22 mm. ; oral sucker, 

 length, 0.08 mm., breadth, 0.1 mm.; pharynx, length, 0.08 mm., 

 breadth, 0.07 mm. ; ventral sucker, length, 0.2 mm., breadth, 0.15 mm. ; 

 ova, 0.051 by 0.033 mm. 



From kingfish: Bull. U. S. Fish Comm. for 1899, p. 462, 1901. 

 One (U.S.N.M. No. 8251), collected September 3, 1908. Measure- 

 ments, balsam: Length, 1.86 mm.; breadth, 0.38 mm.; oral sucker, 

 length, 0.12 mm., breadth, 0.12 mm.; pharynx, length, 0.11 mm., 

 breadth, 0.08 mm.; ventral sucker, length, 0.18 mm., breadth, 0.18 

 mm.; ova, 0.051 by 0.03 mm. Two, collected September 23, 1913; 

 length, in balsam, 1.5 mm. 



From silver hake : Bull. U. S. Fish Comm. for 1899, pp. 282, 290, 

 figs. 38, 39, 1900, p. 474, fig. 335, 1901. Three, collected August 29, 

 1903; small, one with ova. Three, collected August 15, 1907. Six 

 (U.S.N.M. No. 8252), collected August 13, 1928; 1 to 1.75 mm. in 

 length, in balsam. Two, collected August 16, 1928; length, 2 mm.; 

 breadth, 0.46 mm., life. 



From goatfish: Five, collected September 2, 1908, from an 8-cm. 

 fish, seined in Great Harbor; lengths, 1.19 to 1.4 mm. in balsam; 

 papillary fringe around ventral sucker distinct. Six, collected Au- 

 gust 24, 1918, from an 11-cm. fish. Lengths in balsam, 1.4 to 3.12 

 mm. In one of the larger specimens it was noted that there was much 

 variation in the size of the ova in the vicinity of the shell gland. 

 Thus, while most of the ova in the specimen were of the usual size, 

 a maximum of about 0.054 by 0.042 mm., the following variants 

 were noted: 0.048 by 0.033; 0.045 by 0.033; 0.039 by 0.034; 0.033 by 

 0.024; 0.03 by 0.021; 0.033 by 0.018; 0.021 by 0.009 mm. Two 

 (U.S.N.M. No. 8253), collected September 4, 1918, from a 12-cm. fish; 

 slender; one, length, 2.59 mm., breadth, 0.4 mm. ; the other, length, 4.41 

 mm., breadth, 0.36 mm. ; ova, 0.048 by 0.027 mm. 



From toadfish: One, collected September 9, 1913. 



From rudderfish: One (U.S.N.M. No. 8254), collected August 19, 

 1929; measurements in balsam, lateral view: Length, 2.38 mm., 

 breadth, 0.42 mm.; oral sucker, length, 0.17 mm., breadth, 0.17 mm.; 

 pharynx, length, 0.14 mm., breadth, 0.15 mm. ; ventral sucker, length, 

 0.27 mm., breadth, 0.24 mm.; ova, 0.51 by 0.57 mm. 



From summer flounder: Bull. U. S. Fish Comm. for 1899, p. 482, 

 fig. 336, 1901. One, collected October 19, 1903. One, collected 

 August 9, 1904; taper-pointed posteriorly, length, 1.45 mm. One, 



