DERMOPTERI OR LAMPREYS, ETC. 279 



lagoons of the warm parts of South America, and some 

 of the species are five or six feet long, and are able to 

 give such electrical shocks that men and animals are 

 often struck down by them when they go into the water 

 where these fishes abound. 



The Roman Mursense are eels common in the Medi- 

 terranean. They were highly prized by the Romans, who 

 kept them in ponds and fed them ; and they had a cus- 

 tom of placing them alive on the table, in crystal vases, 

 that their guests might admire the variegated colors. 



SUB-SECTION XII. 



THE ORDER OF DERMOPTERI OR MARSIPOBRANCHII OR 



LAMPREYS, ETC. 



THE fishes which belong to this group are the lowest 

 known to naturalists. They are more or less worm-like 

 in general appearance, and have neither pectorals nor 

 ventral fins, and the vertical fins, even when present in 

 some cases, they are wholly wanting are without hard 

 FIG. 350. rays, being extremely soft and 



delicate. Hence, the name 

 Dermopteri, from the Greek 

 derma, skin, and pteron, fin. 



Lamprey, PHromyzon americanus, Another name applied to this 



order, Marsipobranchii, comes 



from the Greek marsipos, a pouch, and bragchia, gills, 

 and alludes to the pouch-like gills of some of these fishes. 

 The Dermopters include the Lampreys, Hags or Myxines or 

 Myxinidse, and the Lancelet or Amphioxus or Amphioxidse. 

 The Lampreys or Petromyzoniclse have the branchial or 

 breathing organ of each side divided by transverse parti- 



