TREMATODES FROM FISHES — ^LINTON 165 



Measurements, average of nine specimens, in balsam : Length, 2.28 

 mm. ; breadth, 0.82 mm. ; oral sucker, length, 0.20 mm., breadth, 0.23 

 mm. ; pharynx, length, 0.20 mm., breadth, 0.13 mm. ; ventral sucker, 

 length, 0.32 mm., breadth, 0.35 mm.; ova about 0.06 by 0.03 mm. 

 Longest of the nine specimens, length, 3.08 mm., breadth, 0.63 mm.; 

 broadest of the nine specimens, length, 2.01 mm., breadth, 0.94 mm. 



Average of nine specimens in balsam, more or less oval-elliptical in 

 outline, post-acetabillar region not tapering: Length, 1.31 mm.; 

 breadth, 0.67 mm. ; oral sucker, length, 0.16 mm., breadth, 0.20 imn. ; 

 pharynx, length, 0.15 mm., breadth, 0.10 mm. ; ventral sucker, length, 

 0.27 mm., breadth, 0.32 mm.; ova, 0.054 by 0.033 mm. to 0.063 by 

 0.039 mm. Longest of the nine specimens, length, 2.10 mm.; 

 breadth, 0.94 mm. ; broadest of the nine specimens, length, 1.98 mm. ; 

 breadth, 1.08 mm. 



Type specimens. — U.S.N.M. No. 8401 (holotype and paratypes). 



Hod. — Filefish {Ceratacanthys schoep-fi). 



Record of collections. — Thirty, collected August 7, 1905. At first 

 pale pinkish, bleaching to translucent bluish white after lying in sea 

 water for some time ; very various shapes, becoming a little more uni- 

 form when placed in 70% alcohol. Measurements in glycerin, com- 

 pressed: Length, 2.94 mm.; breadth, 1.05 mm.; oral sucker, length, 

 0.25 mm., breadth, 0.32 mm. ; pharynx, length, 0.25 mm., breadth, 0.20 

 mm. ; ventral sucker, length, 0.45 mm., breadth, 0.45 mm. 



Five specimens, collected August 19, larger specimens turgid and 

 translucent, smaller specimens yellowish or flesh colored; maximum 

 length, 2.8 mm. 



Four, collected July 29, 1908; turgid, necks very short. 



Numerous, collected August 19, 1908, various shapes. 



Twenty-four, collected July 11, 1910; the living and active worms 

 were yellowish with a faint tinge of red; greatest diameter at level 

 of ventral sucker; neck usually contracted; postacetabular region 

 tapering; the conspicuous excretory vessel was traced from a point 

 a little in advance of the dorsal border of the ventral sucker to the 

 posterior end. The wall of the excretory vessel altered in appearance 

 while the specimen was under observation. Longitudinal and trans- 

 verse fibers in its walls, in certain stages of contraction, gave to the 

 wall a checkered appearance. Inactive specimens were squarish-ob- 

 long in outline, but when flattened under the cover glass they assumed 

 outlines similar to those of the active specimens. Still others were 

 turgid, semitransparent, with their vitellaria much reduced. Two 

 of the small, active distomes were placed in fresh water where they 

 soon became turgid, and then resembled closely the distomes which 

 were inactive when first removed from the intestine of the fish and 



