XII INTRODUCTION. 



the task, I have endeavoured by minuteness of description, aided by correct figures, 

 to render their recognition of the fish already named more certain. I have, also, 

 in consideration of the difficulty of procuring books in remote districts, entered 

 more fully into generic details than is usual in a local Fauna, and likewise given 

 compendious notices of most of the families mentioned in the Regne Animal, 

 borrowing largely not only from that work, but also from the Histoire des 

 Poissons. Cuvier divides the class in the following manner : — 



First Series. FISH PROPERLY SO CALLED. 



A. Upper jaw formed externally of inter maxillaries and moveable labials ; and 



posteriorly of a palatine arch composed of palate bones, pterygoid processes, 

 jugal, petrous, and squamous bones, constituting a sort of interior jaw as in 

 birds and snakes, and furnishing posteriorly an articular cavity for the con- 

 dyle of the lower jaw. 



a. Gills in leaves. 



Order 1. Acanthopterygii. (vide p. 108. F. B. A.) 



2. Malacopterygii abdominales. (p. 109.) 



3. Malacopterygii sub-brachiati. (p. 241.) 



4. Malacopterygii apodes. (p. 267.) 



b. Gills in tufts. 



5. Lophobranchii. (p. 276.) 



B. Labials soldered to the intermaxillaries : palatine arch united to the cranium 



by suture and not admitting of motion. 



6. Plectognathii. (p. 277.) 



Second Series. CHONDROPTERYGII or CARTILAGINOUS FISH. 



A. Gill openings of the ordinary form, having a moveable gill-plate. (Eleuthe- 



ropomi.) (p. 278.) 



7. Sturionide/e. (p. 278.) 



B. Canals communicating with gills having fixed edges, and opening exteriorly by 



one or several holes. (Trematqpneontes.) (p. 287.) 



8. Selachii. (p. 287.) 



9. Cyclostomata. (p. 292.) 



