28 THREE CRUISES OF THE " BLAKE. 



Fig. 206. — Plectromus suborbitalis. }. (U. S. F. C.) 



The snappers and groupers of the tropics surely range below 

 one hundred fathoms, but it seems hardly appropriate to regard 

 any of the true percoids, or any of their very near allies, as 

 really abyssal in habit. 



Some of the scombroids seem to inhabit deep water, espe- 

 cially the Trichiuridae, the so-called cutlass-fishes, which may 

 be considered a deep-sea group. They are long, compressed, of 

 glistening silver color ; they date back to the chalk of Lewes 

 and Maestricht, and occur in the eocene schists of Glaris. A 

 number of pelagic scombroids have been taken under such 

 circumstances as to render it probable that they descend to 

 considerable depths. The lumpsuckers (Liparidse) are well rep- 

 resented by four genera, which have undergone extreme modifi- 

 cations characteristic of abyssal forms. They have soft, cavern- 

 ous skeletons, immensely developed mucous canals, and are soft 

 and flaccid in the extreme. The family of lump-fishes (Cyclop- 

 teridse) is represented below the hundred-fathom line off the 

 Atlantic coast. 



The " ribbon-fishes " may be named with the abyssal groups, 

 although they have never been dredged at any considerable 

 depth, but are known solely from individuals stranded upon the 

 shores or found at the top of the water. The largest of the 

 ribbon-fishes is capable of rapid motion at the surface, and is 

 probably the animal which has most often been taken for the 

 sea-serpent. The " Bermuda sea-serpent," Regalecus Jonesii, 

 was seventeen feet long, and swam with great velocity through 

 the surf, and dashed itself upon the shore. It seems altogether 



