36 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. 



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

 Ferca flavescensCuy.', the wall-eyed pike, Stizostedioii americana, (Cuv. 

 and Val.;) the sauger, 8. grisea (DeKay;) the blue-pike, sp. ii. ; the white- 

 bass, Roccus chrysojhs (Eaf.) Gill; four (?) species of Etheostomoids; 

 Chirostoma sieculum Cope; the sticklebacks, Gasterosteiis inconstans 

 Kirt.; G. nebulosus Agass., aud G. pygmccus Agass.; the lake-pike, Esox 

 lucins Lin.; the muskelluuge, E. nohilior Thomps.; the niud-minuow, 

 Umbra Imi (Kirt.) Gunth ; a few Cypriuodouts; Percopsis guttatus, 

 Agass.; the white-fish, Core</owwsai&?ts Les.; the Menominee white-fish, 

 Coregonns quadrilatendis Eich.; the lake-herrings, Argijrosomus clupei- 

 forinis Mitch., and A. hareiigus Eich.; the speckled-trout, 8almo fonti- 

 nalis Mitch.; the moon-eye, Hijodon tergmis Les.; the saw-belly, Fomo- 

 lohus chry.sochloris Eaf.; the muUet-sncker, Ftyehostomus aureolus (Les.) 

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

 G. 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 (?) species of Cypriuoids; 

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

 cans Les.; the fork-tailed cat-fish, Ictelurus cwrulescens Eaf.; the yellow 

 back-tail, Noturus Jiavus Eaf.; the dog-fish, A^nia calva Lin.; the bill-fish 

 or gav-\nke,Lei)idosteus osseus Lin., and L.platystomus Eaf.; the sturgeon, 

 Acipenser ruhicnndus Les., aud the lamprey, Fetromyzon. In this zone 

 is also found the Amphibian Mcnobranchits lateralis Say. 



[t will be observed that the lawyer, the white-fisb, and the lake- 

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

 not only in the spawuing-season, but at all times. The 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 I).) Invertebrate fauna. The invertebrate fauna of the bottom 

 has been investigated to a limited extent bydredgings. 



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

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

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

 mollusks, mosses, and algte. 



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

 including Drs. Stimpson, Lapham, Andrews, Hoy, aud 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 planarian, and a small mollusk, 

 of the genus Fisidium. The crustaceans were determined 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 



