DESCRIPTIONS: OF) THE: SPECIES. 
FAMILY I. PETROMYZONTIDA®. 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. Petremyzon concolor (Kirtland). LAamprey. 
[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. Zzo teeth 
close 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 II]. POLYODONTID®. THE PADDLE-FISHES. 
2. Polyodon spathula (Walbaum). PADDLE-FISH. 
[Jord. Man. 39. O. St. Surv. 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 oneever 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. 
