62 NATURAL HISTORY OF AMIA CALVA LINNAEUS. 



fins and the tail-spot it is possible to distinguish easily the male of Amia from the 

 female at a distance of from ten to twenty feet. 



In those males taken just before the breeding season the colors are much less 

 brilliant. Thus in 1899 the first males were taken on April 18, and though in breed- 

 ing dress, the colors were not brilliant. The first nest was found on April 23. On 

 April 24 the breeding dress of the males had reached a maximum in only one fish 

 out of six taken on that day. The number of males in which the breeding colors 

 were at the maximum then increased until April 29, when all males were most brilliantly 

 colored. This brilliancy of color lasts certainly until the middle of June, but beyond 

 that it has not been followed. At all seasons, however, the sexes are distinguishable 

 by their colors. 



It is often possible to distinguish individual males by peculiarities of color or by 

 accidents of structure, and thus to identify them as they are encountered from time 

 to time in their native waters. After my attention had been once called to this fact 

 I was able, without taking the fish from the water, to distinguish by color or anatomi- 

 cal peculiarities nearly every male studied. 



I have recorded ten such individual fish. 



No. 1. The tail-spot on one side was comma-shaped, the tail of the comma 

 directed upward. 



No. 2. The tail-spot on one side was comma-shaped, the tail of the comma 

 directed downward. 



These fish were not again encountered, but during the season of 1900 of the 

 nine swarms of which record was kept the males of eight were recognized, in some 

 cases repeatedly, by their individual peculiarities, as follows: 



No. 3. The green-spot male. A conspicuous elongated bright green spot near 

 the dorsal border of the caudal. Two bright orange spots within the yellow border 

 of the tail-spot caudally; a notch in the caudal fin. 



No. 4. The two-spot male. Two tail-spots on the right side. The super- 

 numerary spot was triangular, about two-thirds as large as the normal spot and one 

 inch below and in front of it. 



No. 5. The split-tail male. The caudal fin was horizontally split nearly to 

 its base, below the middle. 



No. 6. The ring male. The yellow border of the tail-spot was flattened in 

 front and was there formed of two distinct spots the whole having the appearance 

 of a finger-ring with two stones set in it. 



No. 7. The white-spot male. On the right side of the head dorsally a well- 

 marked white spot in front of the junction of opercle and head. 



