SMOOTH-TAILED STICKLEBACK. 81 



ACANTHOPTERYGll. WITH HARD CHEEKS. 



THE SMOOTH-TAILED STICKLEBACK. 



Gasterosteus leiurus, Cuv. et V^alenc. Hist. Nat. des Poiss. t. iv. p. 481, 



pi. 98, fig. 4. 

 Pisciculus aculeatus, Rond. Willughby, X. 14, fig. 1. 

 Gasterosteus ,, Penn. vol. iii. pi. 61. 



The third species is the Smooth-tailed Stickleback, in 

 which the lateral plates extend no farther than the ends of 

 the rays of the pectoral fin ; the whole length of the side 

 beyond this being smooth and soft, without scale or fold, and 

 only marked with the linear depressions produced on the 

 surface by the divisions of the lateral muscles. The general 

 colours of the three species are green above, passing into 

 silvery white below. Some exhibit various shades of crimson 

 and purple ; but these colours are more frequent in males than 

 females. Fin-rays : — 



D. ill + 10 : P. 11 : A. 1 + 8 : C. 12. 



