TREMATODES FROM FISHES — ^LINTOlfT 35 



showed that while anterior tentacles were indistinct, their presence 

 was indicated; also some specimens show folds of the uterus extend- 

 ing in front of the ventral sucker. 



From mackerel scad: One (U.S.N.M. No. 8181), collected October 

 25, 1913 ; 20 fishes examined. Length, in formalin, 3.25 mm. ; diam- 

 eter of circle of tentacles, 0.28 mm., of body, 0.33 mm. Ova very 

 numerous, from posterior end to a point 0.47 mm. back of the anterior 

 end. Body minutely spinous. The cirrus pouch extends forward to 

 level of anterior end of second testis ; testes separated from each other 

 by an interval less than the diameter of a single testis, and the ovary 

 is separated from the first testis by an interval a little less than the 

 diameter of the ovary. The vitelline follicles are partly concealed 

 by ova. About 14 follicles can be counted on one side, extending from 

 about the level of the anterior end of the second testis to a point 

 0.08 mm. from the anterior end. Dimensions in balsam: Length, 

 2.87 mm. ; breadth, anterior, 0.17 mm., middle, 0.29 mm., near posterior 

 end 0.18 mm.; anterior sucker, length, 0.14 mm., breadth, 0.14 mm.; 

 diameter ventral sucker, 0.06 mm. ; distance anterior end to vitellaria, 

 0.81 mm., to uterus, 0.49 mm.; ova pointed at one end, 0.024 by 

 0.012 mm. 



From kingfish: Five (U.S.N.M. No. 8182), collected October 26, 

 1912. Length in formalin, 3.22 mm. ; breadth, 0,24 mm. ; about eight 

 of the circle of papillae visible in dorsal view. Measurements in bal- 

 sam : Length, 1.61 mm., breadth, 0.25 mm. ; anterior sucker, length, 

 0.1 mm., breadth, 0.09 mm. ; diameter ventral sucker, 0.05 mm. ; ova, 

 0.024 by 0.015 mm. One specimen showed about 14 vitelline follicles 

 on each side. 



The collection contains examples of this Nannoenterum from two 

 species of ray. Since the occurrence of this parasite in a ray is excep- 

 tional it is probably to be regarded as a case of introduction along 

 with fish in which it was a common parasite. This is probably also 

 the explanation of the frequent macerated condition in which this 

 parasite was found in certain hosts. 



Four (U.S.N.M. No. 8183), collected September 27, 1910, from 

 stomach of clear ray. Length in formalin, 2.76 mm.; breadth, 0.35 

 mm. ; anterior end surrounded by small, spinelike papillae ; body nearly 

 cylindrical, bluntly rounded at posterior end, tapering to anterior end ; 

 anterior, 0.25 mm. of length necklike. Measurements in balsam: 

 Length, 2 mm. ; breadth, 0.32 mm. ; anterior sucker, length, 0.12 mm., 

 breadth, 0.13 mm.; length of tentacles, 0.015 to 0.021 mm.; diameter 

 of testis, 0.18 mm., of ovary, 0.13 mm. ; ova, 0.021 by 0.013 mm. Two 

 of the four mounted specimens have very few spines. The uterus 

 extends from near the posterior end to a point about halfway between 

 the vitellaria and the anterior end. In each of the specimens the ova 



