TREMATODES FEOM FISHES — LINTON 87 



From southern porgy: Bistoiwumi sp., Bull. U. S. Fish Comm. for 

 1899, p. 2-96, fig. 72; p. 458, fig. 376, 1901. One, collected August 19, 

 1903. Measurements in balsam : Length, 0.65 mm. ; breadth, 0.31 mm. ; 

 diameter of oral sucker, 0.07 mm., of ventral sucker, 0.07 mm.; 

 pharynx, length, 0.05 mm., breadth, 0.04 mm. ; ova, 0.068 by 0.032 mm. 

 This distome agrees with the foregoing closely, but the esophagus is 

 very short, and no prepharynx could be seen. The neck was strongly 

 contracted. 



Ten (U.S.N.M. No. 8271) collected August 24, 1910; six porgies 

 examined. One, active in sea water, varied in length from 0.42 to 

 0.84 mm. An average of six gave the diameter of the oral sucker, 

 0.065, ventral sucker, 0.059 mm. In a lot of ten, mounted in balsam, 

 there were noted cases with distinct prepharynx, and very short, or no 

 esof)hagus; others with very short, or no prepharynx and distinct 

 esophagus; others with both prepharynx and esophagus distinct. 

 The vitellaria extend to level of posterior end of pharynx. In details 

 of the anatomy these distomes are in close agreement with those from 

 the rudderfish. 



From cutlassfish: Thirty (U.S.N.M. No. 8272), collected June 18, 

 1913, from one fish. Length of longest, in formalin, 2.15 mm.; 

 breadth, 0.6 mm. Eleven mounted in balsam vary from length, 0.6 

 mm. and breadth, 0.27 mm., to length, 1.26 mm., and breadth, 0.4 mm. 

 Measurements of one of largest in balsam : Length, 1.20 mm., breadth, 

 0.42 mm. ; diameter of oral sucker, 0.075 mm., of pharynx, 0.033 mm., 

 of ventral sucker, 0.072 mm.; length of prepharynx, 0.015 mm., of 

 esophagus, 0.18 mm. ; ova, collapsed, about 0.06 by 0.024 mm. 



The prepharynx is shorter than the pharynx and the esophagus 

 varies from less than the length of the pharynx to twice its length or 

 more. The vitellaria in all cases extend as far forward as the level 

 of the ventral sucker. A second seminal vesicle was distinguished in 

 one. So far as can be made out the anatomy of these distomes agrees 

 closely with those from the rudderfish. 



LEPOCREADIUM RETRUSUM, new species 



Plate 6, Figxiees 50-52 



Body spinose, of nearly same breadth throughout, tapering slightly 

 to anterior end, which is bluntly rounded; posterior end broadly 

 rounded ; oral sucker more or less retracted in all cases seen, smaller 

 than ventral sucker ; pharynx small, prepharynx longer than pharynx ; 

 esophagus about as long as pharynx ; genital pore in front of ventral 

 sucker, a little to left of median line; cirrus pouch large, extending 

 back of ventral sucker and enclosing prostatic cells and a seminal 

 vesicle; a second seminal vesicle connected with the cirrus bulb by a 



