198 



SUBKINGDOM VEETEBEATA. 



The 'Silver-fish is only a variety of the Gold, resulting from 

 artificial treatment. 



The 3arbel, belonging to the same genus, has four beards 

 or barbules hanging from the mouth, probably to aid it in 

 grubbing with its nose in the soft banks for aquatic larvae. 



Fig. Sltl. 



Anguilla latirostris, Broad-nosed Eel. yV. 



Anguillidse (snake-like). — The Common Eel is oviparous, 

 and so tenacious of life as to wander across dewy meadows 

 from pond to pond, its gill-openings being far back and thus 

 protecting the gills from drying. 



ORDER MARSIPOBRANCHII. 



G-eneral Characteristics. — The Pouch-gilled fishes have 

 a cartilaginous skeleton, naked skin, only one nasal organ, 

 and no lower jaw. 



Petromyzonidae (stone-suckers). — Mg. sk$. 



The Lamprey occurs in both salt and 



Fig. 3m. 



Pelnmijzon amerUUnus, Lamprey. 



Mouth of Lamprey. 



