2IO H. H. NEWMAN. 



(Fig. i) does not do this character justice. A far better idea of 

 the prominence of this sexual marking can be obtained from an 

 examination of the illustration in the paper just referred to. 



5. The dorsal and anal fins of the male are much larger and 

 stronger than those of the female and are used as clasping or- 

 gans in spawning. 



6. These fins and all parts of the body of the male that come 

 into intimate contact with that of the female in spawning and 

 courtship are covered with small finger-like papillae that lend to 

 these parts a decided roughness and undoubtedly assist the male 

 in holding the female securely. These organs have elsewhere 

 been designated "contact organs." 



7. During the sexual climax the whole body of the male is 

 suffused with dark pigment, some specimens showing an almost 

 inky blackness on head, cheeks and back. The female, however, 

 retains her normal pale olivaceous tint, or in many cases becomes 

 distinctly paler than during the vegetative season. 



8. The flesh of the female, during the height of the spawning 

 season, becomes softer than usual and the abdomen is greatly 

 distended with ripe ova. 



9. The behavior of the males, during the spawning season, is 

 sharply contrasted with that of the females. The former are 

 spirited and pugnacious, and frequently follow the females about 

 in order to spawn with them. Actual spawning, however, was 

 observed only occasionally in F. majalis, but it is essentially like 

 that of F. hetcroclilKS, which was observed hundreds of times. 

 The behavior of the female is characteristically coy. 



These and a few minor differences between the sexes will serve 

 to render intelligible the account of the individual now to be 

 described. 



Description of the Hermaphrodite Specimen. 



The fish herein described was discovered by merest chance 

 during the progress of some breeding experiments at the Woods 

 Hole laboratories. 



On July 3, 1907, needing a male Fwidulus majalis, I rather 

 hurriedly dipped out of the aquarium what I took to be a large, 

 but decidedly pale, male. Wishing to perform an experiment 



