HISTORY 



THE FISHES 



MASS 



251 



• 



But it is principally valued as lamp 



for this purpose it is superior to 



ob- 



froro. any other fish, and is equal to purified sper 



Massachusetts, Storer 



OKDER III. CYCLOSTOML 



Gills purse-shaped, fixed, opening outwards by several aperture-. Jaws represented 

 by an immovable cartilaginous ring, formed by the union of the j>alatine and mandibular 



bones. Intestinal canal straight and narrow. 



FAMILY XXX. PETEOMYZONIDiE. 



Body elongated, cylindrical, eel-shaped. No pectorals nor ventrals. Fins without 



rays. 



GENUS I. I PETKOMYZON. Lin. 



Sev< 

 strong 



branchial apertures 

 sth. Mouth beneath 



on each side of 



Maxillary ring armed with 



Petromyzon americanus. Lesueur. 



The Great Lamprey. 



(Plate XXXVIII. Fig. 4.) 



Petromyzon marinus, Great Lamprey, Mitch., Trans. Lit. and Phil. Soc. N. Y. i. p. 461 

 Petromyzon americanus, Lesueur, Trans. Amer. Phil. Soc, new series, i. p. 382. 



American lamjrrey, Storer, Report, p. 195. 



American sea lamprey, Dekat, Report, p. 379, pi. 66, fig. 216. 



Storer, Sj^nopsis, p. 265. 



a 



a 



<< 



a 



u 



a 



Color 



Above, olive-brown, mottled with dark brown, almost black, confluent patches 



beneath, of a uniform dull br 



Desert 



Pupils black, irides golden 



The anterior portion of 



body 



cvlindr 



the posterior com 



pressed. A slight carina is observed upon the back. Head rounded, somewhat flattened 



upper portion in front of the ey 



Snout obtuse. Eyes of moder 



The 



distance of the eyes from the snout is less than one twelfth the length of the entire fish. 

 A tubular orifice, a line in its longest diameter, is seen in front of, between the eye*. 

 Posterior to each eye, are seven large branchial apertures, separated about a quarter of 



