46 American Fisheries Society 



mesentery, but the dorsal mesentery ends in the sarne way as 

 in other salmonoid fishes. 



The second set of membranes comprises those pertaining to 

 the genital organs. From each side of the air bladder a peri- 

 toneal fold, termed the mesovarium or mesoarium, extends to 

 each ovary, which contrary to the previously stated observa- 

 tions, almost completely enfolds the ovary. It forms the 

 inner or axial surface of the ovary, and when the ovary 

 is in normal position, extends downward and around and 

 upward on the outer surface, so that the outer surface is 

 completely covered and has no exposed laminae. How- 

 ever, the position of the ovary is such that a compar- 

 tively narrow surface of the edges of egg-bearing laminae, 

 not covered by adherent membrane, is inclined inward in 

 such a manner that the mesovarium lies on the free-egg sur- 

 face forming a covering. The laminae, instead of being situ- 

 ated vertically on the outer surface of the ovary, extend ob- 

 liquely crosswise of the somewhat boat-shaped ovary, and when 

 the ova ripen and burst from their inclosing follicles, instead 

 of falling into the abdominal cavity they are deposited in the 

 groove or angle between the upper edge of the laminae, or free 

 egg surface, and the mesovarium covering; the inner end of 

 each laminae is lower than the outer end. 



If we follow the line of origin of the mesovarium on the 

 surface of the air bladder, it is observed to gradually pass 

 inward and fuse with the mesentery near its posterior termi- 

 nation. The two ovaries are seldom of equal length, the left 

 usually being longer. In a ripe fish the left ovary generally 

 extends tapering nearly to the posterior end of the abdominal 

 cavity, while the right terminates some distance anteriorly to 

 that point. In the case of the shorter ovary, or where both 

 are short, the mesovarium continues from the posterior end 

 of the ovary, uniting with that of the opposite side to form a 

 trough on the upper surface of the intestine behind the pos- 

 terior terminus of the mesentery. This trough near the geni- 



