450 PETROMYZID.E. 



the external apertures. If a Lamprey, while so attached to 

 the side of a vessel, be held with one series of apertures out 

 of the water, the respiratory currents are seen to enter by the 

 submerged orifices, and, after traversing the corresponding 

 sacs and the pharynx, to pass through the opposite branchiae, 

 and to be forcibly ejected therefrom by the exposed orifices. 

 The same mode of respiration must take place in the Mix- 

 ine," (a species of this family to be described hereafter,) 

 " while its head is buried in the flesh of its prey. The 

 cyclostomous fishes thus present an obvious affinity to the 

 Cephalopoda, inasmuch as the branchial currents are inde- 

 pendent of the actions of the parts concerned in deglutition." 



The intestinal canal is small, and extends in a straight line 

 along the abdomen to the anal aperture without any convolu- 

 tion. The Lampreys arc oviparous, spawning late in the 

 spring ; the roe escaping, in both sexes, by a small membra- 

 nous sheath, which has internally at its base five apertures, 

 one leading upward to the intestine, one to each kidney, and 

 one to each lateral cavity of the abdomen. 



The Marine Lamprey, which from its mottled appearance 

 was called P. maculosus by Artedi, has a very extensive geo- 

 graphical range. It is found in the Mediterranean, and from 

 thence northwards in most of the rivers of Europe as far as 

 Scandinavia, during the spring. Professor Reinhardt in- 

 cludes it among the fishes of Iceland, and our countryman 

 Pennant gives it a place in his Arctic Zoology. From a 

 description and figure in the Natural History of the Fishes 

 of Massachusets, by Dr. Smith of Boston, this fish appears 

 to be common in the rivers of North America, attaining a 

 large size in those of the more southern states, but not ex- 

 ceeding seventeen or twenty inches in length in a high 

 northern latitude. Dr. Mitchell also includes this species 

 among his fishes of New York. It is rather common during 



