48 LECTUUE III. 



Suborder 2. Marsipobranchii ( Cyclostomi, Cuvier). 

 Gills fixed, bursiform, inoperculate, receiving the respiratory 

 streams by apertures usually numerous and lateral, distinct from the 

 mouth ; a heart. 



Fam. Myxinoidei, Examples, Myxine, or Hag. 



PetromyzontidcB, Lamprey. 



Ordo II. Malacopteri (^Physostomi, Miiller). 



Endo-skeleton ossified ; exo-skeleton, in most, as cycloid, in a few 

 as ganoid, scales ; fins supported by rays, all, save the first sometimes 

 in the dorsal and pectoral, soft or jointed ; abdominal or apodal ; gills 

 free, operculate ; a swim-bladder and air-duct. 



Suborder 1. Apodes. 

 Fam. Symbranchidce, Example, Cuchia. 

 MiiranidcB, Eel. 



Gymnotidce, Gymnotus. 



Suborder 2. Abdominales. 

 Fam. Heteropygii, Example, Amblyopsis. 



Endo-skeleton ossified ; exo-skeleton in some as cycloid, in others 

 as ctenoid, scales ; inferior pharyngeal bones coalesced ; swim-bladder 

 without duct. 



Suborder 1. Malacopterygii. 

 Fam, Scomber-esocidcB, Example, Saury-pike. 



Suborder 2. Acanthopterygii. 



Fam. ChromidcB, Example, Chromis. 



Cyclo-LahridcB, Wrasse. 



Cteno-LabridcB, Pomacentrus. 



