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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 88 



sucker subterminal, with a tuberclelike prolongation of the body in 

 front; no prepharynx; pharynx about half the diameter of the oral 

 sucker, or less. In most cases the esophagus appeared to be shorter 

 than the pharynx, on account of the very contractile neck, but in the 

 specimen sketched, fig. 301, the esophagus is longer than the pharynx, 

 and has rather thick walls. The genital pore is on the median line 

 behind the forking of the intestine; cirrus smooth; cirrus pouch 

 elongate, fusiform, enclosing cells of the prostate and, at its posterior 

 end, the seminal vesicle. The posterior end of the cirrus pouch is 

 at the anterior edge of the ventral sucker, or slightly overlapping 

 it dorsally. Testes near posterior edge of ventral sucker, diagonally 

 placed; ovary behind testes and in front of the two vitellaria, which 

 are near the posterior end, and transverse, or, in some cases slightly 

 diagonal. The uterus extends from the level of the vitellaria to the 

 ventral sucker ; ova about 0.04 by 0.02 mm. 



Table 29. — Measurements of five speoimens of Genarclies infirmiis in balsam 



Measurements 



Length 



Breadth, level of oral sucker 



Breadth, level of ventral sucker 



Breadth, near posterior end 



Oral sucker, length.. 



Oral sucker, breadth 



Pharynx, length,. 



Pharynx, breadth 



Ventral sucker, length 



Ventral sucker, breadth 



Ova, 0.03G by O.OIS to 0.042 by 0.021 mm 



Mm. 

 2.31 

 .15 

 .35 

 .08 

 .15 

 .14 

 .07 

 .08 

 .29 

 .28 



Type specimens. — U.S.N.M. No. 8317 (holotype and paratypes). 



Host. — Chinook salmon {Oncorhynchus tschawytscha) . 



Record of collections.— Eight (U.S.N.M. No. 8317), collected May 

 17, 1898, from stomach of young salmon. Pinole, San Pablo Bay, 

 California. 



Six, collected November 17, 1898, from stomach of young salmon. 

 Battle Creek, California. 



GENARCHES species 



Plate 23, Figubes 303, 304 



Body smooth, long oval-elliptical, not differing much in breadth 

 throughout, bluntly rounded at each end; ventral sucker approxi- 

 mately twice the diameter of the oral sucker; pharynx about half 

 the diameter of the oral sucker; no prepharynx; esophagus, if any, 



