402 THE ANGLER-NATURALIST. 



CHAPTER XIII. 



Series II. CARTILAGINOUS FISH*. Family CTCLOSTOMATA J. 



Order II. CHONDROPTERYGII BRAN- Genus PETROMYZON '. 



CHIIS FIXIS t. 



THE COMMON OR SEA LAMPREY. 



(Petromyzon marinus ||.) 



Characteristics common to the Family of " Round-mouthed" fish. 

 No pectoral or ventral fins : body ending in a circular fleshy lip, with 

 a cartilaginous ring supporting it : no proper ribs or solid gill-arches, 

 and the vertebra reduced to cartilaginous rays not readily distin- 

 guished from one another. Nostrils opened by a single orifice. In- 

 testine straight and narrow. 



THE characteristics of the Lampreys as a genus are 



* CJiondropterygii, from Gr. chondros, cartilage, and pterygion, a fin : 

 Fish without bones in their structure. (See p. 38.) 



t " Cartilaginous fish with fixed gills." (See p. 38.) 



} Cyclostomata, " Round- or Sucking-mouthed fish," from Gr. cyclos, 

 a circle, and stoma, a mouth. 



Petromyzon, " Stone-sucker," from petros, a stone, and myzo, I 

 suck, Gr. || marinus, Lat., of the sea. 



