192 FISH GALLERY. 



Trachypteriformes (Ribbon-fishes) . 



Ribbon- The division Trachypteriformes is a small one, containing the 

 two families Lophotidse and Trachypteridse, the former with a 

 single genus, Lophotes, the latter with two, Trachypterus and 

 Regalecus (fig. 91). The body is much laterally compressed, 

 usually ribbon-like in shape, whence the popular name " Ribbon- 



fishes. 



Fig. 91. — Ribbon-fish, Regalecus gladius. 



fishes." The dorsal fin extends from the top of the head to the 

 tail, its rays are simple and not spinous, and the anterior rays are 

 longer than the others. The pectoral fin has a nearly horizontal 

 base; the scales are minute or absent. These fishes occur in the 

 deeper parts of the Atlantic, North Sea, Mediterranean, and 

 Pacific. In the family Lophotidse the vent is situated far back, 

 and behind it is a short anal fin, but in the Trachypteridse there 

 is no anal fin and the vent is situated at about the middle of the 

 length of the body. The mouth is very protractile in the Trachy- 

 pteridse, moderately so in the Lophotidse. 



The Deal-fish or Northern Ribbon-fish, Trachypterus arciicus, 

 of which a coloured drawing (885) of the natural size is shown, 

 has six fiu-rays in the pelvic fin, and the caudal fin consists of 

 two parts, the upper of which is large and upwardly directed. 

 Specimens of the Deal-fish are occasionally stranded upon the 

 coasts of Scotland and Norway. In the young Trachypterus (886) 

 the fin-rays of the first dorsal and the pelvic fins are remarkably 

 long, and the dorsal fin-rays are provided with arrow-head lappets 

 of skin set at regular intervals. A specimen of Trachypterus 

 crktatus from the Mediterranean is shown, mounted in a glass 

 vessel of alcohol (884) . 



