78 



Order XI. SELACHOSTOMI. 

 Family 26. POLYODONTIDyE. 

 Genus 69. Polyodon, Lacepede. 



130. Polyodon spathula, Wall— Shovkl- fish; Paddle- fish; Spoon-bill 



Cat; Duck-bill Cat. 



(Bui. II, 69; Polyodon folium.) 

 Abundant in the Mississippi and Illinois rivers, and especially in the ponds 

 and lakes in the bottoms of these streams. Rarely, if ever, ascending smaller 

 streams, and not collected by us in any of the interior lakes. Not known 

 from Lake Michigan. Hausman Bros., a firrm of fishermen at South Chicago, 

 reported the capture of a single specimen of this species in the Calumet river, 

 probably an emigrant by way of the caoal. 



Class II. MARSIPOBRANCHII. 



(The Myzonts.) 



Order XII. HYPEROARTIA. 



Family XXVII. PETROMYZONTID^. (The Lampreys.) 



Genus 70. Ichthyomyzon, Girard. 



Silvery Lampreys. 



131. Ichthyomyson argenteus, Kirt. — Silvery Lamprey. 



(Bui. II, 70; Ammocoetes argenteus, Ammocoetes hirudo.) 



Collected by us chiefly in the Illinois and Ohio Rivers, attached to shovel- 

 fish, cat-fish, sturgeon, buffalo, and other large species, as taken in the nets 

 of the fishermen. 



Genus 71. Ammoccetes, Dumeril. 

 Brook Lampreys. 



132. Ammoccetes niger, Raf. — Small Black Lamprey. 



A small species, which we have found only in small streams in the north- 

 ern part of the State. Especially abundant in spring, at the spawning sea- 

 son. 



SUMMARY AND CONCLUSION. 



The especial characteristics of the fish fauna of the State as distinguished 

 from other zoological areas, are the preeminence of the Catostomidae and the 

 Siluridae, (the suckers and the cat-fishes,) and of the sunfishes, darters and 

 minnows, the shovel fish and the various species of gars, and the dog-fish, are 

 likewise among the characteristic features of our fauna, as is also the exces- 

 sive abundance of the hickory shad. 



The limited share of Illinois in Lake Michigan, not extending into watar of 

 more than twelve or fifteen fathoms, gives us but a small group of species 

 peculiar to the great lakes: viz., the common white fish, the lake herring, the 

 lake trout, the muskallunge, and the burbot. 



Numerical Data. 



It will be seen that the fishes of Illinois, as shown by this list, represent 

 132 species, which are here distributed among 71 genera and 27 families. 



