TREMATODES FROM FISHES — LINTON 59 



date. They are much smaller and are sagittate, or long-oval, in out- 

 line instead of linear. They are somewhat macerated, all spines 

 missing, except a few of the oral spines on one specimen. The great- 

 est breadth is at about the middle of the postacetabular region, 

 whence they taper rather uniformly to the anterior end, and are 

 bluntly rounded posteriorly. The ventral sucker is much larger than 

 the oral; pharynx longer than broad, and longer than the oral 

 sucker; prepharynx as long as or longer than pharynx; esophagus 

 short or lacking. The seminal vesicle extends far back of the 

 ventral sucker; testes near the posterior end, one following and 

 touching the other; ovary relatively small, at right anterior border 

 of first testis; uterus between ovary and ventral sucker; vitellaria 

 diffuse, follicles small, extending, in a specimen 2.28 mm. in length, 

 to within 0.35 mm. of the ventral sucker. In optical section the neck 

 shows a deeper layer of strong, transverse fibers, which are some- 

 what sinuous, and produce the effect of a lattice with lozenge-shaped 

 openings, and an outer layer of fine, longitudinal fibers (pi. 4, 

 fig. 31). 



Measurements in balsam: Length, 3.22 mm., maximum breadth, 

 0.59 mm.; oral sucker, length, 0.14 mm., breadth, 0.15 mm.; pharynx, 

 length, 0.28 mm., breadth, 0.14 mm,; ventral sucker, length, 0.27 

 mm., breadth, 0.28 mm.; oral spines, length, 0.021 mm., breadth, 

 0.012 mm. ; ova, 0.06 by 0.03 mm. 



These distomes bear some resemblance to Lechradena edentula 

 Linton ^-, which should be regarded as a species of Stephanostomum. 



STEPHANOSTOMUM species 



Host. — Leather jack {Oligoplites saurus). 



Two fragments of a distome (U.S.N.M. No. 8212), collected July 

 24, 1924, are here noted. 



Measurements in balsam: Anterior fragment: Length, 2.8 mm.; 

 breadth, 0.85 mm.; length of seminal vesicle, 1.26 mm., breadth, 

 0.18 mm.; ova, 0.069 by 0.036 mm. The anterior end of the seminal 

 vesicle is about at the same level as the anterior follicles of the 

 vitellaria, which are 0.49 mm. from the anterior end of the frag- 

 ment on one side, and 0.63 mm. on the other. Posterior fragment: 

 Length, 4.62 mm.; breadth, 0.7 mm.; first testis, length, 0.8 mm., 

 breadth, 0.46 mm,; second testis, length, 0.87 mm., breadth, 0.46 mm.; 

 ovary, length, 0.26 mm., breadth, 0.28 mm.; distance between ovary 

 and first testis, 0.15 mm., between testes, 0.22 mm.; from second 

 testis to posterior end, 1.3 mm. Vitellaria, composed of rather 

 coarse follicles, fill the posttesticular space, the spaces between 

 testes and those between ovary and testis. They are interrupted at 



" Carnegie Inst. Washington Publ. 133, pp. 46, 47, fig. 87, 1910. 



