234 FAMILY OF RIBAND-SHAPED FORM. 



and large individuals sometimes appear. Thus, one 

 has been caught in a harbour chasing small mullet ; 

 and others, similarly employed, are frequently de- 

 tected on the shores of Nice. 



Gen. XXXIY. Trachypterus, formerly Bog- 

 marus^ and Gymnog aster. This genus has a caudal 

 fin singularly placed, not at the termination of the 

 tail, but over its extremity, projecting upwards. 

 The lateral line is garnished with scales armed with 

 a sharp hook ; the jaws are furnished with teeth ; 

 the pectoral fins are of medium size, and the ventrals 

 often greatly developed : the form of their body is 

 greatly compressed and elongated, like the blade of 

 a sword ; all the upper part of the body is furnished 

 with a dorsal fin, the anterior portion of which, 

 sometimes distinct, rises from the head like a plume. 

 The fins are remarkably brittle. 



T. Bogmarus. The Deal-fish, or Yaagmaer (PI. 

 XY.), has been observed in the British seas only on 

 the shores of Orkney, and especially in Sanda Bay, 

 where upwards of a dozen have been obtained be- 

 tween the years 1817 and 1829, some alive, but 

 most dead. Dr. Duguid of Kirkwall communi- 

 cated descriptions to Dr. Fleming, which were 

 published in Loudon's Magazine. (Mag. of Nat. 

 Hist., iv. 215). These specimens were imperfect, 

 and so, necessarily, were the descriptions. Of the 

 one caught alive, we are told that it was three feet 

 long, having the body excessively compressed, par- 

 ticularly towards the back, where it did not exceed 

 a table-knife in thickness ; breadth nearly five 



