748 



THE AMERICAN NATURALIST [Vol. L 



My examples 92 to 96 mm. Spawning fishes of this . spe- 

 cies were obtained from April until the middle of August. 



In the West African killifish {Fundidus nisorius) the 

 male has the outer portions of the anal rays covered with 

 little spinules. It is also quite likely that the anal fin is 

 furnished with spinules in the spawning Fundulus ber- 

 mudce. 



The barred killifish {Fundulus diaphanus) common in 

 the fresh waters of the east, from Maine to Carolina, is 

 quite brilliant in the spawning-season. In the male the 

 spinules are arranged as little points, like those of the 

 mummichog, though as the fish is smaller they are less 

 conspicuous. The scales and fins other than the anal are 

 without spinules. Spawning males 60 to 70 mm. In the 

 female a well-developed basal anal sheath extends around 

 the front of the anal fin. Spawners of this species in full 

 color were obtained from April until the middle of Au- 

 gust. 



The zebra-fish {Fundulus zebrinus) of the Mississippi 

 Valley region has long been noted for its prickly appear- 

 ance. Jordan and Evermann state, presumably with 

 reference to spawning fish, * 1 in males the margins of both 

 dorsal and anal fins are evenly rounded, the anal the 

 higher, its rays beset with minute white prickles." My 

 examples show it differs from any of the preceding spe- 

 cies in the male having the sides with the scales minutely 

 spinescent along their edges. The area of spinescent 

 scales extends from the head in some examples, in others 

 for variable distances, back to caudal base, and always 

 with its greatest development over the base of the anal 

 fin. On the back the spinules gradually disappear, and 

 the same is true on the under surface of the caudal pedun- 

 cle. Further, an additional modification is seen in the 

 presence of spinules on the inner or hind surfaces of the 

 ventrals, though these fewer than on the anal rays. On 

 the front of the anal fin the spinules are best developed, 

 though irregularly distributed on the segments of the fin- 

 rays, here and there appearing crowded or sparse. 



