83 FISH GALLERY. 



( 



Order IV. PHYSOSTOMl. 



Bony fishes with all the fin-rays articulated, only the first of the 

 dorsal and pectoral fins sometimes ossified ; ventral fins, if present, 

 abdominal, without spine. Air-bladder, if present, with a pneu- 

 matic duct (except in Scombresocidai) , 29 families : — 



1. Silurida. 2. Characinidce. 3. Cyprinida, 4. Haplochitonidts. 

 5. Sternoptychidce. 6. Scopelidee. 7. Stomiatidm. 8. Salmonidte. 

 9. Percopsidce. 10. Galaxiidce. 11. Mormyridts. 12. Esocidce. 

 13. Umbridcs. 14. Scombresocidce. 15. Cyprinodontidm. 16. 

 Heterapygii. 17. GonorhynchidtB. 18. HyodontidcB. 19. Osteo- 

 glossidce. 20. Clupeidce. 21. Chirocentridce. 22. Bathytkrissidee. 

 23. Alepocephalidce. 24. Notopteridce. 25. Hahsauridce. 26. iVo- 

 tacanthidtB. 27. Gymnotidte. 28. Symbranchidce. 29. Mureenidte. 



The Silurida, or Cat-fishes (Cases 18, 19), are a large family, 

 represented by numerous genera, which exhibit a great variety of 

 form and structure of the fins. The skin is naked or protected by 

 osseous scutes, but without scales ; barbels are generally present. 

 These fish inhabit the fresh waters of all the temperate and 

 tropical regions ; a few only enter the sea, but keep near the coast. 

 The European species {Silurus glanis, fig. 68) is found in the 



Fig. 68. 



Wels (Silurus glanis). 



waters east of the Ehine, and is, next to the Sturgeon, the largest 

 of European freshwater fishes, attaining to a weight of 300 or 

 4001b. The "Bayad" {Bagrus bayad) is common in the Nile, 

 and grows to a length of over five feet ; it is eaten. Arius, of 



