10 Bulletin 47, United States National Museum. 



lingual tooth with a median depression ; buccal disk large, with numerous 

 teeth arranged in concentric-series ; dorsal fins separate, the second joined 

 to the caudal. 



North Atlantic, ascending rivers ; one species known, the largest of the 

 lampreys. (7rrpa, stone ; //" to suck.) 



8. PETROMYZON MARINUS, Linnseus. 



(GREAT SEA LAMPREY ; LAMPREY EEL.) 



Head large, longer than the branchial area ; buccal disk large, with 

 numerous conical teeth, arranged in obliquely transverse series, 4 to 7 in 

 each row ; lateral teeth 011 each side of mouth bicuspid, the other teeth 

 simple; dorsals low, well separated; the second dorsal with a depression 

 on the tail; lips moderately fringed; males and often females, in spring, 

 with an elevated fleshy ridge on back before dorsal fin ; 64 muscular im- 

 pressions between gill openings and vent. Color bluish brown, mottled 

 with blackish confluent patches, rarely nearly plain; whitish below. 

 Length 24 to 36 inches. Atlantic coasts of Europe and North America, 

 southward to Chesapeake Bay, abundant northward, ascending streams 

 in the spring to deposit its spawn. (Eu.) 



Petromyzon marinus, LINN^US, Syst. Nat., Ed. x, 1758, 230, European Seas ; (after Artedi); 

 GUNTHER, Cat., viii, 501 ; JORDAN & GILBERT, Synopsis, 11, 1883 ; JORDAN & FORDICE, Ann. 

 Ac. Sci.N. Y.,1886, 283. 



Petromyzon americanus, LE SUEUR, Trans. Am. Phil. Soc. Phila., i, 383, 1818, Coast of Massachu- 

 setts; STOKER, Fish. Mass., 251, pi. 38, fig. 4,1867. 



Petromyzon nigricans, LE SUEUR, I. c., 385, 1818, Massachusetts. 



Ammocceles bicolor, LE SUEUR, 1. c., 386, 1818,(larva), Northampton, Massachusetts. 



Pelromyzon appendix, DE KAY, N. Y. Fauna: Fishes, 381,1842, (young). Providence; Hudson 

 River. 



? Pelromyzon lamotleni, LE SUEUR, in DeKay, I. c., 382, 1842, no locality. 



Represented in fresh waters by 



8a. PETROMYZON MARINUS UNICOLOR, (De Kay). 



A dwarfish form similar to the common lamprey ; darker and more uni- 

 form in color, the dorsal ridge larger, the fins closer together ; found land- 

 locked in the lakes of northern and central New York ; abundant in 

 Cayuga Lake. 



Ammocceles unicolor, DE KAY, N. Y. Fauna: Fishes, 383, 1842, (larva), Lake Champlain. 

 Petromyzon marimts domains, Wilder MS., JORDAN & GILBERT, Synopsis, 869, 1883, Cayuga Lake. 



(Type, No. 31368) ; GAGE, Wilder Quarter Century Book, 1893, 420. 

 Pelromyzon marinus unicolor, MEEK, Ann. Ac. Sci. IT. Y., 1886, 284. 



7. ICHTHYOMYZON, Girard. 

 (RIVER LAMPREYS.) 



IcUhyomyzon, GIRARD, Pac.R.R.Sur., x, 381,1858, (argenleus). 

 Scolecosoma, GIRARD, I. c., 385, 1858, (concolor, larva). 



Allied to Petromyzon, but with the anterior lingual tooth divided by a 

 median groove. Dorsal fin continuous, with a broad notch. Small 

 lampreys; confined to fresh waters in eastern United States. (lx&i>s t 

 fish; [ivfa, to suck.) 



