No. 600] ORNAMENTATION IN THE KILLIFIS HES 749 



Length 48 to 75 mm. The female has a broad basal sheath 

 around the front of the anal fin. Length 51 to 63 mm. 



The little green killifish (Fundulus floripinnis) of the 

 South Platte Eiver basin has the male with the scales 

 along the middle of the side, especially above the base of 

 the anal, with minute prickles along their edges. Similar 

 prickles also occur on the rays of the anal fin, though 

 with irregular distribution on the segments. They usu- 

 ally appear better developed along the front anal edge. I 

 have also seen a few minute prickles above the eyes. In 

 length these males were 47 to 57 mm. This species be- 

 longs to the section Zygonectes Agassiz, so called as the 

 fishes were said to swim in pairs. Doubtless this would 

 refer to the spawning-habits or when spawning, for at 

 other times they do not appear to swim in pairs. As in 

 the brown killifish {Fundulus lucice), another member of 

 the Zygonectes group, I have never seen them swimming 

 in pairs, and Ellis claims the same for the little green 

 killifish. 



In the stud-fish (Fundulus stellifer) the males have 

 very minute spinules along the anal rays and along the 

 edges of their scales above the fin. They are also irregu- 

 larly placed. Length 82 to 99 mm., and the females 73 

 mm. long have a well-developed basal anal sheath at the 

 front of the fin. The related Fundulus catenatus shows 

 similar ornamentation in the male, though my material is 

 inadequate for detailed comparison. 



In the rainwater-fish (Lucania parva) males in high 

 color, taken in June, differ from any other killifish I have 

 examined in the presence of minute spinules on the upper 

 surface of the snout, in some cases even encroaching on 

 the interorbital space. No other spinules occur. The 

 muzzle of the male is also modified or decidedly obtuse, 

 suggestive of the fat-head minnows (Pimephales). 



The pursy-minnows {Cyprinodon variegatus) when in 

 brilliant spawning-dress, in the case of the males, are ex- 

 tensively provided with minute spinules. These extend 

 all along the edges of the scales on the head, front predor- 



