390 



BULLETIN OF THE BUREAU OB' FISHERIES. 

 Sciaenops ocellatus. Red Fh-um. 



PROTOZOA. 



1. Myxobolus (Henneguya) sp. [Fig. 56.] 



1901. — Aug. 10, the pyloric cseca and beginning of the intestine of the fish examined on this date 

 were almost completely covered with white bodies 2 mm. or less in diameter. Twenty-four of these 

 bodies were counted in a space 15 mm. square. The sporozoa were oval, about 0.013 mm. in length, 

 0.010 mm. in greatest breadth and 0.006 mm. thick, with a slender posterior spicule of about the same 

 length as tin- body of the sporozoon. The cell wall is relatively thick, the two oval bodies of the 

 usual shape and of a faint greenish color. When first liberated in sea water there appeared to 1 a- a 

 third body behind the oval bodies. Later this could not he seen. The caudal spicule was straight in 

 most, hut not infrequently was curved. 



The fish had been caught several hours before it was examined and the mucous membrane had 

 sloughed off, leaving the cysts exposed on the inner Bide of the intestine when it was opened; they 

 showed quite plainly also from the outside, their color being an opaque dead white. Numerous 

 minute, highly retractile bodies were seen to be scattered among the sporozoa where the cysts were 

 flattened on the slide. 



See also under Arehosargus probatocephalus and TYachinotus carolinus. 



NEMATODES. 



T. HeteraHs sp. [Fig* 24, 25.] 



( "Ascaris ('.') sp.," from Paralichthys dentatixs No. 6, p. 481, pi. vn, figs. 57-61, Parasites of Fishes 

 of the Woods Hole Region.) 



1901. — Aug. 9, 1. This specimen has two prominent post-anal papillae. There is no indication of 

 spicules. Dimensions in millimeters, life: Length, 5; diameter, anterior 0.4, middle0.5, at anai aper- 

 ture O.HS; distance of anal aperture from posterior end 0.18; length of oesophagus 0.67. 



A specimen similar to this was found in the flounder (see Xo. 6 under Paralicldhys edbiguttus). It 

 was at first supposed to he a male, but upon examination it was found to he a female, the reproductive 

 aperture being situated two-fifths of the whole length from the posterior end. 



See also under Leiostomus, and Lophopsella, and introduction for remarks on Heterakis. 



:-'.. Scolex polymorphic Rudolphi. 



1901.— Aug. .'io, few. July 30, few. 



TREMATOIIKS. 



4. Distomum vitellosum Linton. [Figs. 176, 177.] 



1901. — Aug. 9, numerous; great variety of shape and size as in ifenticirrhus americanus. In certain 

 stages of little contraction the border of the ventral sucker, which is undulate when moderately 

 contracted, is deeply lobed or even fimbriate. Some of the specimens while still in sea water had 

 become rigid and turgid, with prominent ventral sucker. In the latter case the characteristic border 

 of the ventral sucker is obliterated. In one specimen under pressure the testes appeared to be lobed. 

 Relative dimensions agreed with published descriptions. Aug. 15, 6. Aug. 30, 12. In this lot a 

 surprising variety of shape, and particularly in the condition of the ventral sucker, was found. In 

 some the ventral sucker was seen to be surrounded by four lobes, each of which is denticulate or 

 fimbriate, having four or more processes. When seen in dorsal or ventral view this feature is not 

 conspicuous, hut in lateral view, when the ventral sucker is prominent and its border uncontracted, 



