166 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



placed in sea water. The fish from which these distomes were ob- 

 tained had been dead for several hours. 



Fifty, more or less, collected July 13, 1911, from intestine of host. 



Fifty, or more, collected August 21, 1915; some yellow, others 

 white. 



Fifteen, collected July 28, 1920, about 2 mm. in length. 



Fifty-six, collected August 27, 1926 ; relatively shorter and broader 

 than the usual forms. 



Eighty-five more or less (U.S.N.M. No. 8401), collected by Dr. E. 

 B. Krumbhaar, August 17, 1929. Two types, agreeing with fore- 

 going descriptions; one white, obtuse, inactive; the other broadest 

 at ventral sucker, j^ostacetabular region more or less elongated, color 

 yellowish tinged with red, active. 



Genus STENOCOLLUM Stafiford, 1904 



STENOCOLLUM FRAGILE (Linton) 



Distomum fragile Linton, Bull. U. S. Fish Comui. for 1899, pp. 282, 295, figs. 



68-70, 1900; ibid., p. 466, 1901. 

 Stenocollmn fragile (Linton), Stafford, Zool. Anz., vol. 27, p. 487, 1904. 



One example of this distome (U.S.N.M. No. 8402), somewhat 

 macerated, was collected from the intestine of a sunfish {Mola m.oIa) 

 July 19, 1926. 



Genus DERETREMA Linton, 1910 



DERETREMA FUSILLUS Linton 



Plate 25, Figubes 341-344 



Deretrema fusillus liixTON, Carnegie Inst. Washington Publ. 133, pp. 49, 50, 

 figs. 102-104a, 1910. 



Four distomes from a flyingfish, collected on three different dates 

 at Woods Hole, are referred to this species, although, as was the case 

 with the Tortugas material, showing considerable variation among 

 themselves. 



The body is smooth, fusiform, broadest at level of ventral sucker ; 

 no prepharynx, esophagus not longer than pharynx; intestinal rami 

 extend back of ventral sucker, but not to the posterior end; genital 

 pore at left side of neck ; cirrus pouch large, in front of ventral sucker 

 and enclosing the seminal vesicle and prostate; testes behind ventral 

 sucker, opposite. Ovary in front of right testis, at right posterior 

 border of the ventral sucker; seminal receptacle behind ovary. The 

 vitellaria consist of a few follicles lateral to the ventral sucker and 

 testes ; shell gland and yolk reservoir between the testes. The uterus, 

 beginning at the shell gland, fills with its voluminous folds all of the 

 post-testicular region of the body and also a considerable portion of 

 the region behind and dorsal to the ventral sucker. The metraterm, 



