8 Bulletin 4/, U filled States National Museum. 



south to Cape Cod. Not abundant in America. "Intiat et devorat 

 Pisces; aquam in gluten mutat." (Linnajus). (Eu. ) 



Myxine glnlinnsa, Linn;eu8, Syst. Nat., Ed. x, 650, 1758, Atlantic Ocean; GCnthee, Cat., viii, 



510, 1870; Putnam, Proc. Bost. Soc. Nat. Uist., 1873, 1.35. 

 Mi/xine Hmosa, GniAiti), Proc. Ac. Nat. Sci. Phila., 1858, 22:i, Grand Menan, Bay of Fundy; 



Jordan & Gilhert, Synopsis, 5, 1883. 

 GaslruhmiichHn ovcits. Block, Iclith., xii, pi. 413, CO, 1705, Denmark, etc. 



Order C. HYPEROARTII.* 



(The Lampreys.) 



Nasal duct a blind sac, not penetrating the palate. This order is 

 equivalent to the single family Petromyzonidce. (vKspuya, palate; apring, 

 complete; i. c, entire.) (Petromyzontid^., Giinther, Cat., viii, 499-509.) 



Family IV. PETROMYZONID^. 

 (The Lampreys.) 

 Bodj' eel-shaped, subcylindrical anteriorly, compressed behind ; the 

 mouth nearly circular, suctorial, usually armed with horny teeth, or tooth- 

 like tubercles which are simple or multicuspid, resting on jjapillaj ; those 

 immediately above and those immediately below the cesophagus more or 

 less specialized ; eyes developed in the adult ; gill openings 7, arranged in a 

 row along the sides of the " chest ; " nostril on top of the head Just in front 

 of the ej'es; lips present, usually fringed; dorsal fin more or less deeply 

 divided by a notch ; the posterior part commonly continuous with the anal 

 around the tail; intestines with a spiral valve; eggs small. 



These animals undergo a metamorphosis; the young are usually tooth- 

 less and have the eyes rudimentary. Separate generic names (Animoccctes, 

 Scolceosoma , Chilopterus) had been applied to these larval forms, before it 

 was discovered that they were the normal young of the true lampreys. 



Genera about 7; species about 15; of the rivers of temperate regions. 

 They attach themselves to fishes and feed by scraping off the flesh with 

 their rasp-like teeth. Most of them ascend rivers or brooks at the spawn- 

 ing season, after which very many of the individuals die. (Petromyzon- 

 TID/E, Giinther, Cat., viii, 499-509.) 

 n. Second dorsal continuous with caudal. 



h. Supraoral lamina ("maxillary ") and infraoral lamina (" mandible ") destitute of toetli, 

 " the armature of the lamprey typo hoing obsolescent; " otherwise as in Pctromy- 

 zon ; sea lampreys. Bathymyzon, 5. 



6?;. Supraoral and infraoral lamin.x with tcoth or tooth-like tubercles. 



c. Sujiraorul lamina contracteil, tlio armature consisting of 2 or 3 cusps placed clo.«o 

 together; discal teeth numerous, in concentric series ; anterior lingual teeth 

 with a median depression or groove ; buccal disk large in the adult, con- 

 tracted in the young. 



Anterior lingual tooth with a deep median groove and terminating in an in- 

 curved point ; dorsal fin divided. Large lampreys; auadromous. 



Petromyzon, 6. 



. *?".'" "ioo!''''^'' 'i''co"nt "f t'>e North American Lamprevs, see Jordan & Fordice, Ann. N. Y. 

 Ac.bci., 1880. I'or an pxcellentaccount of the lifehistory of certain species see Gage, in Wilder 

 Quarter-Century Book, 1893, pp. 420-479. 



