226 SWIM-BLADDER OF FISHES A DEGENERATE GLAND. — PRINCE. 



Fig. 2. Swim-bladder of Corvina (after Cuvier and Valenciennes). 



Fig. 3. " " ** a Sciainoid (after Giinther). 



Fig. 4. " " '* Pogonias chromis (after Giinther). 



Plate 23* 



Abdominal viscera of young sturgeon viewed from above, showing 



capacious swim-bladder (s b. ) 

 The same showing upper side of swim-bladder (s b.) cut away to show 



the interior with opening of pneumatic duct (y. ) and radiating fibres. 

 Newly hatched gaspereau (Pomolobus psevdharengus, Wilson) showing 



large swim-bladder (s b.) and anterior cornu (co7'n.) x 20. 



Post-larval smelt {Osmertis) 15. 5 mm. long. x 7. 



Post-larval Thwaite-shad (Ciiipea finta) 20 mm. long, showing small 



elongated swim-bladder (s b. ) x 5. 

 Post-larval goby {Gobius) 11 mm. long with conspicuous ovoid closed 



swim-bladder (s b.) x 10. 



Head of climbing perch of India {A)iabas scandtns) showing supra- 

 branchial organ above the gill-chamber proper. 

 Swim-bladder (s b.) of Heterohranchus divided into two globular sacs. 

 Swim-bladder of Malaptenirus showing a third chamber posterior to 



two incomplete rounded sacs, outer tunic partly lifted away and 



exposing second layer. 



*Figs. 1 and 2 after J. A. Ryder (Bulletin U. S. Fish Comm. Vol. VIII, 1888.) ; 4 and 

 6 after Ernst Ehrenbanm, (Wissenschaft. Meeresunsuch, Erster Band Hef , Beitr. 

 3. Naturgeshichte einig). Elbflshe. 1891) ; 6 after E. W. L. Holt (Sci. Trans Roy. 

 Dub. See Vol. IV . 1891); and 8 and 9 after Redouts in Histoire Naturelle (Egypt): 

 Poissons, by Geoffroy St. Hilaire. 



