184 Proceedings of the Biological Society of Washington. 



Billy Lake Landing and in a bog on Billy Island. On Dec. 26, 1916, 

 Mr. Francis Harper took it at Minnie Lake Narrows; on Floyd's Island 

 Prairie, on Jan. 4, 1917, and on Chase Prairie, Jan. 12, 1917. 



In 1881 R. E. Earll took two females in Indian River and in 1884 Jordan 

 described it. In Dec, 1890-Jan., 1891 Albert J. Woolmann found 2 males 

 and 3 females in the Santa Fe river (Suwanee River system). With 

 two specimens {Zygonectes mannii Hay) taken by Mann and Davidson 

 in Yellow Water River, western Fla., we have 9 specimens. It is wide- 

 spread in the swamp and the appearance of such a large series with no 

 conscious effort made to collect them and non-recognition of the species 

 by us during the 1912-1913 trips shows it to be a common form in the 

 swamp. Later in 1916-1917 Mr. Harper was on the lookout for it. He 

 had examined some of the 1912-1913 material. 



In total length these specimens range from 10 mm.-25 mm., the largest 

 being a male; the standard lengths 8.5-21 mm. The head varies from 

 3V4-3 3 A in the length, the depth 4 1 /* t -5. the lateral row of scales 27-32. 



This beautiful little killifish is smaller than Lucania goodei and averages 

 larger than Heterandria formosa. With both it has some phases of color- 

 ation in common. In coloration these 63 specimens fall into two groups; 

 those with lateral black ocellus just in front of the origin of the anal (fe- 

 males) ; and those without the spots (males). Both sexes have the caudal 

 ocellus in our series except for one specimen which may be male or female 

 and which is without anal or caudal ocellus or any dark bands of minute 

 dots. Woolmann with 2 males in hand declared they have no caudal 

 ocellus but all the males of our series have it. In several it is smaller than 

 in the female and a part of the last brown transverse bar, but in the largest 

 specimen of the 63, a male, the black ocellus has replaced the transverse 

 brown bar. In all the males there is no real clear-cut ocellus just above 

 and in front of the origin of the anal fin, yet in all there is a suggestion of 

 it in an indistinct collection of black dots. The males have from base of 

 caudal to front of the dorsal origin from 5-7 more or less distinct transverse 

 brown bars in the younger individuals, 3-4 in the older individuals. In 

 the latter group these bars are restricted to the caudal peduncle and the 

 oldest males have a tendency to lose transverse bands entirely and become 

 punctate all over the body. In the male the dorsal and anal may be 

 very narrow (D. 4 or 5, A. 6 or 7) and the tip of dark punctate fins reach 

 almost if not to the base of the caudal. In the females these fins are plain, 

 never approach the base of the caudal and usually have 6 or 7 rays in the 

 dorsal and 8-10 rays in the anal. Thus the anal fin may be modified 

 though Woolmann's two specimens did not show it. If both sexes be 

 considered the dorsal may be from 4-7 in rays and the anal from 6-10. 

 Another puzzling condition is that several of the males are amongst the 

 largest specimens of the series. These males have the tips of the ventral 

 fins black. The males have not the lateral brown bands of the female 

 but in addition to the basal transverse brown band (in both sexes) of the 



