188 THE ROYAL SOCIETY OF CANADA 



One copepod which contained an individual of this species was 

 determined as a female of Acartia clausi Giesbrecht, common at the 

 mouth of the St. Croix River according to Willey (30). 



10. Hemiurus levinseni (Odhner). 14, pp. 106-7. 



Encysted in the muscles of the small Clupea harengus L. from the 

 stomach of the Salmon — see under Species No. 8, above. 



Three specimens, associated in the above location with encysted 

 Derogenes various are referred to this species since they agree satis- 

 factorily with Odhner's description of the species as given by Looss 

 (14). The following measurements are of the largest of the three 

 from a coronal series of sections : Length of body (appendix invaginated) , 

 1-18, width opposite ovary, 0-31; width of oral sucker, 0-15, of 

 acetabulum, 0-14; length of ductus hermaphroditicus, 0-12; egg, on 

 the average, 0-028 X 0- 014mm. The vitelline glands in all of the 

 three specimens are so closely applied to each other, immediately 

 behind the ovary, that at first sight they appear to form a single mass 

 similar to that of the genus Aphanurus Lss., but on closer inspection 

 can be seen to be distinctly separated from each other. This close 

 apposition is doubtless due to the longitudinal contraction of the 

 worms, the glands themselves, like the ovary and testes, being much 

 flattened antero-posteriorly. The caudal appendage is comparatively 

 short, not more than one-quarter of the length of the body proper in 

 the two smallest individuals where it is protruded, and relatively much 

 smaller in the largest in which it is invaginated. The intestinal crura 

 are very large in these young specimens — all of them containing 

 eggs, however — and occupy much more of the body than do the 

 reproductive organs and ducts. 



No specimens were found free in the stomach of the Salmon, 

 but since Stafford reports H. appendiculatus for Solmo salar, a further 

 search would doubtless have brought some to light. A re-examination 

 of his material might possibly necessitate the recognition of two or 

 more species. 



11. Brachyphallus crenatus (Rud.). 14, pp. 157-8. 



Habitat, similar to that of the preceding species, also in the 

 anterior part of the intestine of one of these food-fishes. 



Only two specimens were found, one of which got damaged in the 

 clearing fluid. The following data apply to the other and smaller 

 of the two, the one found free in the intestine of the small herring: 

 Length, 1-06; greatest width, opposite ovary and vitelline glands, 

 0-26; length of appendix, completely invaginated, 0-23; diameter of 

 oral sucker, 0-132, of acetabulum, 0-137, of pharynx, about 0-07; 

 average length of egg (from sections of the broken specimen), 0-025, — 

 although this one also contained eggs. From these measurements it 



