128 Part 111. — Twenty-fovrth Annual Report 



The Number of Rays in th.p Paired Fins and Caudal Fin. 



Species. 



Length 

 of the 

 Fish. 



Sex. 



Vent- 

 ral Fin. 



[ 



Pecto- 

 ral Fin. 



Caudal 

 Fin. 



G. luscus. 



Cm. 

 24 

 26 

 27 

 27 



d 

 S 

 6 



6 



: 



6 



19 

 18 

 20 

 20 



38* 

 40 





Average, 



6(4) 



19(4) 



39 (2) 



G. minutus. 



14 

 14 

 19 

 21 

 22 

 23 

 24 

 25 



2 

 2 



£ 

 2 

 2 

 2 



6 

 6 



6 

 6 

 6 

 6 

 6 

 6 



19 

 19 

 20 

 20 

 18 

 18 

 19 

 19 



39" 



39 



38 





Average, 



6(8) 



19 (8) 



38-6(3) 



G. esmarhii. 



15 

 15 

 16 

 18 

 21 



2 



! 



2 

 2 



6 

 6 

 6 

 6 

 6 



20 

 19 

 19 



20 

 20 



40" 





1 



Average. 



i 



6(5) 



19-6(5) 





In all the specimens examined the same number of rays was obtained 

 in the ventral fin, viz., 6. In the case of the pectoral fin there is a 

 fairly similar amount of variation in each species ; and the number of 

 caudal rays is apparently very similar in the three species. The absence 

 of variation in the ventral fin is to be expected, from the fact of there 

 being so few rays. That may be one of the factors, but it may also be 

 in part due to the fact that the ventral fin has a well fixed function in 

 the genus — that its function, whatever it may be, is exactly similar in 

 each of the species in which its rays remain the same. 



The Lengths of the Ventral and Pectoral Fins. 



The authors of " The Scandinavian Fishes " state in their description 

 of G. minutus that the tip of the ventral fin reaches past the anus. This 

 is not constant. The ventral fin has a long filamentous tip in the 

 three species. 



