REPORT ON FISHES. PART I : COBITIDAE 



301 



chaniLer of the I)la(](ler lias assumed the form of the typical Cyprinid bladder and probably 

 functions in exactly the same way. 



The type of bladder found in A^. kiingcssaniis (Text-figure IB) shows that the spec 



les 



Fkuire 1. Various types of air-bladder found in Nnnailtiliis (after Rendalil). Various magnified. A: 

 .V. Iiiiljcrljucnsis Rend.; B: N. kiingcs.minis (Kessl.) ; C: A'. pafillo-Iabiatus (Kessl.) ; D : A^. yarkandnuis Day; 

 E: A^. hsulschonrnsix Rend.; F: A', barhatnia (Liiui.). a = portion of bladder enclosed in bone; 6 = duct con- 

 necting; the enclosed and the free portions of the air-bladder; r = anterior chamber of the free portion of the 

 bladder; rf = posterior chamber of the free portion of the bladilcr ; c = pneumatic duct connecting the air-bladder 

 with oesophagus ; g ■= gut. 



has reverted again to a ground habit of life in comparatively swift currents. Its long, nar- 

 row and thick-walled posterior portion shows that the bladder is losing its utility as a hydro- 

 static organ. In this connection reference may be made to the modification of the swim- 



