DESCRIPTIONS OF THE SPECIES. 



Family I. PETRO^IYZONTID^. The Lampreys. 



Systematic zoologists do not include lampreys with the fishes, 

 but put them into a separate Class, differing from the true fishes'in 

 having very imperfectly developed skeletons. The skeleton in 

 this Class is simply a cartilaginous vertebral column, without dis- 

 tinct skull, jaws, shoulder girdles, limbs or ribs. The gills have 

 the form of fixed sacks, with circular openings, six or more on each 

 side of the " neck." 



1. Petroniyzon concolor (Kirtland). Lamprey. 



[Jord. Man. 5. O. St. Surv. 2.] 



Eel-shaped, bluish silvery or mottled with yellowish, mouth 

 disk-shaped, set with about four circles of small teeth. Two teeth 

 £lose together in front of the opening of the gullet. Reaches the 

 length of 14 inches. 



This species comes into the rivers from the lake in the latter 

 part of May, when they may be found attached to old logs and 

 stones ; at other seasons they are seldom seen, but are occasionally 

 found attached to large fish in pound nets. 



On the 22nd of May, 1887, I took several that were full of 

 ripe eggs, (about the size of No. 8 shot,) in Vermillion river. 



Family IL POLYODONTIDiE. The Paddle-fishes. 



2. Polyodon spathula (Walbaum). Paddle-fish. 



[Jord. Man. 39. O. St. Suiv. 3.] 



A queer fish, with a long paddle-like snout overhanging a 

 broad mouth ; head with flap and snout more than half the total 

 length ; body spindle-shaped, mostly smooth, olivaceous. 



I know of but one ever caught in the Great Lake region. That 

 one was taken in a pound net near Vermillion, in 1874, and was 

 stuffed as a curiosity and exhibited in a store window for some 

 years ; it is still in existence. 



