Putnam.] 158 [Xov. 19, 



oped as a broad band, and the eggs occupy a considerable portion, at 

 least one-half, of the distance from the free edge, the large or mature 

 eo-gs only extending from the walls of the ovary and forming the fringe. 



In Mijxine the peritoneal outlet is single, and behind that of the 

 intestine, and there is a small opening in the membrane over the 

 terminal portion of the intestine, which allows communication from 

 both sides of the intestinal canal with the peritoneal outlet. In the 

 Chilian Bdellostoma this internal communication does not exist, but 

 there are two peritoneal outlets behind the anal opening, affording 

 direct passages from each side of the intestinal canal. The opening 

 on the right side, which is the side occupied by the ovary, is 

 larger than the other, and the left opening in Bdellostoma and the 

 passage over the intestine in Myxine, are probably simply for the pur- 

 pose of furnishing a passage for such eggs as may get pushed under 

 the intestine to the left side. 



From this comparison of the details of the principal points in the 

 anatomy of these two genera, it will be seen that all the modifications 

 are very slight, and will not warrant the separation of the genera 

 into distinct families, as proposed by some authors, simply from the 

 difference in the position of the gill openings. I therefore agree with 

 Dr. Giinther in retaining both genera in the family Myxinidae. 



As was the case in Myxine, so in Bdellostoma, have I been unsuc- 

 cessful in finding a specimen that is unquestionably a male, though in 

 one specimen there are no eggs developed, and in place of the wide 

 ovarv there is a simple tube that here and there contains masses of 

 cellular matter, much more developed posteriorly, which has the ap- 

 pearance of a testis. With this exception all the large lot of speci- 

 mens are undoubted females with the eggs in various stages of develop- 

 ment, the same as noticed in Myxine. In several specimens the eggs 

 are all very small, in others there are from fifteen to twenty that are 

 much larger than the rest in the ovary, and in still other specimens 

 the development of the egg case has commenced on the large eggs, 

 and the first formation of the hooks at the ends of the egg are seen 

 as Granulations, while in still other specimens, in which the large e^crs 

 are from an inch to an inch and a quarter in length, the red color of 

 the case can be seen at each end of the eggs, showing the formation 

 of the horny case developing from the ends to the centre. 



In one of the jars containing a number of the fishes that were 

 very much decayed, I found among the mass two eggs which were 

 probably just ready to be laid when the fish was caught. These 



