TREMATODES FROM FISHES — ^LINTON 103 



sucker; cirrus smooth; cirrus bulb near left dorsal margin of ven- 

 tral sucker, and extending back of ventral sucker, enclosing the pros- 

 tatic cells and a seminal vesicle at its posterior end. There is a sec- 

 ond seminal vesicle connected with the base of the cirrus bulb by a 

 short vas deferens. The second seminal vesicle is, in some cases, rela- 

 tively large, in others it is small and obscured by the ova. Testes 

 two, situated toward the posterior end, one following the other 

 closely, and usually slightly diagonally placed, in some cases slightly 

 lobed. Ovary profoundly lobed, as many as twenty lobes were 

 counted in a few instances, situated ventrally at the anterior border of 

 the first testis. Seminal receptacle elongated, at the left side of the 

 ovary and first testis. Laurer's canal enters the seminal receptacle at 

 its posterior end. The uterus lies between the ovary and the ventral 

 sucker. The thick-walled metraterm lies on the left side of the cirrus 

 pouch; ova from about 0.06 by 0.04 mm. to 0.07 by 0.05 mm. in bal- 

 sam, the shells rather thin and usually collapsed in balsam mounts; 

 vitellaria diffuse, from posterior end to ventral sucker, their breadth 

 on the margins often from one-fourth to one-third the breadth of 

 the body ; yolk reservoir at posterior border of ovary. The excretory 

 vessel at the posterior end of the body extends forward to about the 

 anterior end of the first testis. Measurements in balsam: Length, 

 3.12 mm.. ; breadth, 1.24 mm. ; oral sucker, length, 0.27 mm., breadth, 

 0.28 mm.; pharynx, length, 0.18 mm., breadth, 0.25 mm.; diameter of 

 ventral sucker, 0.25 mm. ; ova, 0.07 by 0.04 mm. An average of seven 

 distom.es, maximum length 3.12 mm., minimum 1.40 mm., gave the 

 following results: Oral sucker, length, 0.19 mm., breadth, 0.22 mm.; 

 pharynx, length, 0.14 mm., breadth, 0.18 mm.; ventral sucker, length, 

 0.19 mm., breadth, 0.21 mm. 



Hosts. — Smooth puffer {Lagocephalus I a£vi ff akis) , toracod {Micro- 

 gadus tomcod), puffer {Sphoeroides maculatus). 



Record of collections. — From smooth puffer: Proc. U. S. Nat. 

 Mus., vol. 20, pp. 537, 538, pi. 53, figs. 1, 2, 1898; Bull. U. S. Fish 

 Comm. for 1899, p. 464, 1901. One, collected July 17, 1906. 



From tomcod: One (U.S.N.M. No. 8299), collected June 8, 1914. 

 Measurements in balsam: Length, 2.38 mm.; breadth, 0.98 mm.; 

 diameter of oral sucker, 0.21 mm., of pharynx, 0.17 mm., of ventral 

 sucker, 0.19 mm.; ova, 0.066 by 0.033 mm. Pharynx with sinuous 

 anterior border. 



From puffer: Bull. U. S. Fish Comm. for 1899, p. 464, 1901. Fifty- 

 two (U.S.N.M. No. 8300), collected July 9, 1904, from intestines of 

 two fishes. Nine, collected August 17, 1904. Twenty-eight, collected 

 May 31, 1905. Most of these came from a piece of intestine of the 

 host 40 mm. in length, preserved in formalin. Twelve, collected by 

 Dr. Irving I. Field, July 8, 1905, from intestine of the host; white, 

 squarish distomes. Thirty-four, collected August 6, 1906, from two 



