Miscellaneous. 319 



Deep-water Fauna of Lake Michigan. By P. R. Hor, M.D. 



At a distance of sixteen to twenty miles off Racine the water in 

 Lake Michigan is from fifty to seventy fathoms deep. The bottom, 

 at these depths, is composed of an impalpable dark-coloured mud, 

 interspersed with depressions containing quantities of partially 

 decayed leaves intermingled with the muddy deposits. It is on these 

 " mud flats " that the fishermen capture, in gill-nets, the largest and 

 finest whitefish and trout. 



The food of the whitefish had never been ascertained. In order 

 to solve this problem, I secured large quantities of the stomachs of 

 fish caught in various depths ; by diluting the ingesta, I was enabled 

 to determine on what the fish subsisted. During these investiga- 

 tions I became deeply interested in the new forms of animal life that 

 swarmed in the deep water— fish that never visit the shore, crusta- 

 ceans that live only in the profound depths of the lake. I discovered 

 three species of fish, four species of small crustaceans, and one mol- 

 lusk, all new to science. The fish I sent to the Smithsonian Insti- 

 tution at Washington : they were placed in the hands of that accom- 

 plished naturalist, Prof. Theodore Gill, who described and named 

 them. 



WTien I sent the fish to Prof. Baird, I asked him to whom I 

 should send the crustaceans ? who was the best authority on that 

 branch of natural history ? His answer was, we had in the West 

 the very man, the best authority in America on the Crustacea, Dr. 

 William Stimpson, Secretary of the Chicago Academy of Science. I 

 record here this fact in justice to Prof. Stimpson and the West. 



Two of the fish belong to the genus Argyrosotmis, a genus pro- 

 posed by Agassiz to include that section of whitefish having a pro- 

 jecting under jaw. 



The Argyrosomus Hoyi, Gill, is the smallest of the whitefish so far 

 found in any of the great lakes, it being only about 8 inches in 

 length, and weighing one fourth of a pound. The " Mooneye," as it 

 is called by the fishermen, is an excellent pan-fish ; but its small size 

 renders it unsuitable for market. Trout devour large numbers of 

 these little beauties, as they constitute a large share of their food. 

 The Mooneye is only found in water over forty fathoms. 



The Black-fin, Argyrosomus nigripinnis, Gill, is a large and beau- 

 tiful fish, having black fins. It has never been caught in less than 

 sixty, and does not occur abundantly in less than seventy fathoms. 

 During the sunmier of 1871 there was not a single Black-fin taken 

 off Racine, as the fishermen did not go so far into the lake as they 

 did the previous season. 



The third species of fish was taken from the stomach of a trout, 

 caught in the deepest water. It belongs to the Cottus family, and 

 is closely allied to Triglopsis Thomj^sonii , Girard, if not identical. 

 Triglopsis Thompsonii was taken (by Prof. Baird) from the stomach 

 of a Lota maculosa caught in Lake Ontario in 1850, since which 

 time not a specimen has been taken, I am informed by the Professor, 

 unless this be the same fish taken now from the trout, as before 

 mentioned. Prof. Gill thinks it is probably an undescribcd species, 



