36 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



(Lac.) Gili; the rock-bass, Amhloplites rupestris (Eaf.) Gill; the perch, 

 Perca flavescens Guy.', the wall-eyed x)ike, Stizostedion americana, (Cuv. 

 and Val. ;) the Sanger, S. grisea (DeKay ;) the blue-pike, sp. u. ; the white- 

 bass, Boccus chrysops (Rat) Gill; four (?) species of Btheostomoids ; 

 Chirostoma siocidum Cope; the sticklebacks, Gasterosteus inconstans 

 Kirt.; G. nehulosus Agass., and G. pygmwus Agass.; the lake-pike, Esox 

 lucms Lin.; the muskellunge, E. nohiUor Thomps.; the mud-minnow, 

 Umbra limi (Kirt.) Gunth ; a few Oypriuodouts; Fercopsis guttatus, 

 Agass.; the white-&sh, Cor ego n us alb us hes.; the Menominee white-iish, 

 Coregonus quadr Hate rails Eich.; the lake-herrings, Argyrosomus clupei- 

 formis Mitch., and A. harengus Eich.; the speckled-trout, Salmo fonti- 

 nalis Mitch.; the moon-eye, Hyodon tergisus Les.; the saw-belly, Fomo- 

 lobus chrysochloris Eaf.; the mullet-sucker, Ftychostomus aureolus (Les.) 

 Agass.; the spotted-sucker, F. fasciatus (Les.;) the long-snouted sucker, 

 C. hudsonius Les.; the common pink-sided sucker, Catostomus communis 

 Les.; the black sucker, Hylomyzon nigricans (Les.,) Agass.; the carp, 

 Carpiodes cyprinus (Les.,) Gunth., and eighteen (f) species of Cyprinoids; 

 the bull-head, Amiurus catus, Lin.; the great lake cat-fish, Amiurus nigri- 

 cans Les.; the fork-tailed cat-iish, Ictelurus cwrulescois Eaf.; the yellow 

 back-tail, Noturusjiavus Eaf.; the dog-fish, Amia calva Lin.; the bill-fish 

 or gur-inke^Lepidosteus osseus Lin., and L.platystomus Eaf.; the sturgeon, 

 Acipenser rtibicundus Les., and the lamprey, Fetromyzon. In this zone 

 is also found the Amphibian Menobranchus lateralis Say. 



It will be observed that the lawyer, the white-fish, and the lake- 

 trout, are found in all depths in more or less abundance. This is a fact, 

 not only in tiie spawning-season, but at all times. Tlie trout, however, 

 are comparatively rare inside of a depth of about thirty fathoms in the 

 deeper lakes, except during the spawning-season ; and the lawyers are 

 only taken in quantities outside of forty fathoms in the spring of the 

 year, 



(19 b.) Invertebrate fauna. The invertebrate fauna of the bottom 

 has been investigated to a limited extent by dredgings. 



This work was initiated by the Chicago Academy of Sciences, in the 

 year 1870, in the shallow water off Chicago Harbor. Dr. Stimpson re- 

 ported finding but little life in this vicinity — insect larvte, a leech, small 

 mollusks, mosses, and algne. 



Later in the season a tug was employed at Eacine, and a party, 

 including Drs. Stimpson, Lapham, Andrews, Hoy, and Mr. E. W. Blatch- 

 ford, made dredgings in from thirty to sixty-four fathoms, resulting 

 in finding the lake-bottom thickly inhabited by two genera of small 

 crustaceans, Mysis and Gammarus, a i>lanarian, and a small mollusk, 

 of the genus Fisidium. The crustaceans were deteryiined by Dr. Stimp- 

 son to be the same as those which Dr. P. E. Hoy had taken from the 

 stomach of the white-fish, in a partially digested state. 



In August of 1871, under the direction of General C. B. Comstock, of 



