SALMON AND TROUT IN ALASKA. 17 



the caudal; a dark blotch at base and front of dorsal; tips of front anal rays immacu- 

 late, forming a distal white stripe along front of fin. 



A fingerling 58 mm. in length (pi. ii, fig. 4) has a depth of 4 in body; head 3.5; 

 eye 3 in head; pectoral 1.5; dorsal (longest ray) 1.33; anal 1.25; ventral 2 (some 

 of the first dorsal and anal rays are variably produced) ; gillrakers, 8-14, longest one-half 

 diameter of pupil, spanning about 2 interspaces. 



Markings much as in earlier stages, but with additional markings on back. Short 

 oval or triangular blotches appear between the parr marks, and numerous small, 

 round, dark spots become irregularly scattered over entire upper surface, including 

 top of head. The orange tints of the iry and smaller fingerlings largely disappear at 

 about this size, the time of the change varj-ing greatly in different localities. In the 

 same degree the falcation of anal and dorsal shows local and indi\'idual variation, but 

 it is always notable. The tips of the first 4 to 6 rays of both these fins, with the outer 

 membrane, retain the orange color or become white, to form a stripe about half the 

 width of the pupil at the margin of the fin ; this lies upon a submarginal band of black 

 of similar width. The distinctness of these bands is variable, but in no case are they 

 entirely absent in fingerlings of 40 to 100 mm., or even more, when in fresh water. 

 At a certain point the elongated rays seem to stop growth in extension while the 

 remainder of the fin continues its normal increase in size until the permanent form 

 has been reached, after which all the growth proceeds together. Examples of 130 to 

 150 mm. show traces of the peculiarity of both growth and color, but later there is no 

 variation from the normal shape as found also in the king. 



A sea-run yearling (pi. iv) from Karluk Beach, Jvme IS, 1903, 150 mm. in length, 

 had depth 4.75; head 4; eye 3.66 in head; snout nearly equal to eye; pectoral 1.5; 

 dorsal 2; anal 2.8; ventral 2; gillrakers 9-14, longest equal to diameter of pupil, 

 spanning about 3 interspaces (in adults from IJ to 2 times pupil, sparming 2| to 4 inter- 

 spaces). Life colors (Rutter) "back olive brown, thickly spotted with black, dorsal 

 dusky, except last ray is pale. Caudal yellowish by transmitted light, tip dusky, the 

 dusky portions greater on lobes; pectoral yellowish; parr marks distinct; iris some- 

 what golden." In alcohol 11 parr marks quite distinct, a little broader than inter- 

 spaces and depth about half depth of body, spots on back round, the largest about J 

 diameter of pupil, covering top of head and baek as far as lateral line — extending on to 

 upper edge of caudal; anal and pectorals with very few punctulations, lower parts 

 silvery. 



The Sockeye, Oncorhynchiis nerka (^Walbaum). 



The sockeye fry at time of hatching measures some 24 mm. in total length, the sac 

 itself about 9 mm., varying in indi\-iduals. The yolk sac is approximately cylindri- 

 cal in general outline, sometimes slightly deeper (dorso-ventrally) at the posterior 

 end. It has little tendency to become pointed at the posterior ventral extremity, 

 as in the coho. 



The ventral walls become completely united and the yolk disappears externally 

 when the yoimg sockeye m,easures about 32 mm. in total length. At this stage both 

 dorsal and ventral outlines are arched (the dorsal the more in alcoholic specimens 

 by reason of the contraction of the softer ventral tissues). The greatest depth is 

 near the middle of the body just in front of the dorsal, about 4.75 to 5.5 in length 

 to base of caudal rays (end of scaling). In poorly nourished examples the depth 

 is greatly decreased in proportion to the length. Head about 3.75; nose rotinded, 

 blunt, length about equaling half diameter of eye; eye about 2.5 in head; pectoral 

 and dorsal about 2; anal and ventral about 2.66 in head; gillrakers 5-14, in length 

 about two-fifths diameter of pupil, spanning 2 to 3 interspaces. 



General color silvery, becoming dusky alK>ve. There is less tendency to metallic 

 iridescence than in the coho, and the fins do not show the orange tints of the latter. 



