66 



BULLETIN OF THE BUREAU OF FISHERIES. 



mental barbeL The variation is exhibited in the following table, based on 25 specimens from Port 

 Ludlow, the type locality of aix, and o from San Juan Island. Both pectorals are listed in each 

 specimen. 



Nine specimens from Sitka show a tendency to 8 dorsal and 12 anal rays, but do not otherwise differ 

 from typical aix: 



From Funter Bay, Lynn Canal, and from the southern shore of the Alaska Peninsula, oiu- material 

 agrees in having almost equally 11 or 12 anal rays, in having almost exclusively 12 pectoral rays, and in 

 the decided tendency to 3 instead of 2 median plates on breast. The barbel is still short. The following 

 table includes 12 specimens from Funter Bay, 9 from Yakutat Bay, 2 from Chignik Bay, and i from 

 Sannak Island. As their range of variation and prevailing mode is the same, they are not given 

 separately. 



Unalaska material re tains the short barbel and has the unpaired median plates on breast prevailingly 

 2 in number, as in aix generally. The fin rays are more numerous than in any form yet considered, and 

 as the tendency in the aix series is toward increase in fin rays to the north, the Unalaska form may be 

 considered an extreme in that series. The following table gives the variation in 20 specimens obtained 

 at Unalaska May 26, 1906: 



The shores of Bristol Buy and northward to Bering Strait are occupied by typical barbatu, which 

 has a comparatively long slender barbel, usually 3 plates in the median series on the breast, 12 rays in 

 the pectoral and a reduced number in the dorsal and anal fins. In this series the greatest reduction in 

 the number of rays in the vertical fins takes place at the extreme northern limit of its range, the reverse 

 being the case in the aix series. The type of barbata had the following characters: 



Dorsal VI-7, anal 9; pectoral 12; plates 3. 



