48 REPORT OF NEW JERSEY STATE MUSEUM. 
Class CYCLOSTOMES. 
The Lampreys. 
Naked eel-shaped animals, known by the absence of jaws, limbs 
and ribs, also without coat-of-mail, and by the presence of a 
brain. 
Family PETROMYZONID. 
The True Lampreys. 
Body compressed behind. Eyes well developed in adult, rudi- 
mentary in young. Mouth partly inferior, disk-lke and formed 
for sucking. Lips, fringed. Horny teeth in adult resting on 
papillz in mouth, though in young toothless. Nostril on top of 
head close in front of eyes. Intestine with spiral valve. Eggs 
small. Dorsal fin somewhat notched. 
Found attached by means of the sucker-like mouth to other 
fishes on which they feed by scraping off the flesh with their 
horny teeth. Ascending streams in the spring to spawn. 
Genus PETROMYZON Linnzeus. 
The Lampreys. 
Petromyzon marinus Linnzus. 
Lamprey. Sea Lamprey. Lamper Eel. River Lamprey. Green 
Lamprey. Shad Lamprey. Nine Eyes. 
Head, to first gill opening, 9; depth 11. Body elongate with 
trunk compressed. A median ridge down back to dorsal. Head 
broad. Snout long. Eye circular, without lids, and a little less 
than last third in space between tip of snout and first gill-opening. 
Mouth large and with fringed lips. Teeth conic, placed in 
oblique series with innermost largest and superior of which are 
