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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 88 



From dollarfish: 20 (U.S.N.M. No. 8258), collected July 18, 1923; 

 small, slender distomes, tapering anteriorly and posteriorly, with 

 four short papillae on both anterior and posterior borders of the 

 ventral sucker; length, free in sea water, 1.5 mm.; diameter, lateral 

 view, maximum, 0.11 mm., near posterior end, 0.07 mm. ; diameter of 

 oral sucker, 0.09 mm., of ventral sucker, 0.15 mm. ; ova, 0.042 by 0.024 

 mm. The testes vary from subtriangular to oval-elliptical in outline. 



Measurements in balsam (lateral view) : Length, 1.54 mm., breadth, 

 0.18 mm.; oral sucker, length, 0.11 mm., breadth, 0.08 mm.; pharynx, 

 length, 0.1 mm., breadth, O.OG; ventral sucker, length, 0.17 mm., 

 breadth, 0.18 mm. ; ova, 0.048 by 0.024 nam. 



Table 18. — Measurements of the testes in five specimens of 

 Cymbephallus vitellosus 



From common gurnard: One (U.S.N.M. No. 8259), collected 

 August 28, 1907. Measurements in balsam: Length, 1.54 mm., 

 breadth, 0.31 mm. ; oral sucker, length, 0.13 mm., breadth, 0.11 mm. ; 

 pharynx, length, 0.11 mm., breadth, 0.08 mm. ; ventral sucker, length, 

 0.21 mm., breadth, 0.18 mm.; ova, 0.05 by 0.03; length of esophagus, 

 0.13 mm. About four short papillae on anterior border of ventral 

 sucker. 



From winter flounder: Bull. U. S. Fish Comm. for 1899, p. 486, 

 fig. 340, 1901. 



From bonito : Bull. U. S. Fish Comm. for 1899, p. 446, 1901. One, 

 collected July 25, 1904. 



From common mackerel : Bull. U. S. Fish Comm. for 1899, p. 445, 

 1901. Two, collected July 20, 1918; from stomach of a mackerel 

 about 25 cm. in length. Slender, tapering from level of testes to each 

 end; esophagus a little longer than pharynx; characteristic lobes 

 around ventral sucker well shown in one. Measurements in balsam : 

 Length, 1.54 mm.; breadth, 0.4 mm.; oral sucker, length, 0.13 mm., 

 breadth, 0.13 mm.; pharynx, length, 0.11 mm., breadth, 0.1 mm.; ven- 

 tral sucker, length, 0.24 mm., breadth, 0.24 mm. ; ova, 0.051 by 0.03. 



Certain small distomes, most of them less than 1 nun. in length, 

 but containing ova, from young mackerel, 18 to 27 mm. in length, 

 collected in July and August, 1918, 1919, and agreeing closely with 

 this species, are here recorded. Measurements in balsam: Length, 

 1.34 mm., breadth, 0.46 mm. ; oral sucker, length, 0.14 mm., breadth, 



