*2S CATECHISM OF 



CHAPTER VI. 



Of Prickly finned Apodal Fish. 



Q.,How many genera are found of prickly- 

 finned Apodal Fish ? 



A. Three: 1. The Ophidium. 2. The Tri- 

 chiurus. 3. The Xiphias. 



Q. How many species compose the genus Ophi- 

 dium ? 



A. Of the genus Ophidium, or Gilthead, there 

 are four species, of which the Ophidium-barbatum 

 will serve as a specimen. It has a small head, the 

 upper jaw rather longer than the under, and both 

 beset with a great many small teeth. It is from 

 eight to fourteen inches in length, is found in the 

 Adriatic and Mediterranean seas, but is not much 

 esteemed for the table. 



Q. Is the genus Trichiurus numerous ? 



A. No ; it contains only two species, Argenteus 

 and Electricus. 



Q. Describe the first of these species, 



A. Thrichiurus Argenteus, or Silver Trichiure, 

 has the body of considerable length, and shaped 

 like a sword ; the whole fish, except the fins, is of 

 a brightish silver colour, with a lateral yellow line 



