576 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 



Males of P. aurantiaca in 7 collections (UMMZ, USNM), taken 

 from April 19 through October 3, lack tubercles. One of these 

 specimens, a 132 mm. male taken April 29 (UMMZ 129572, Tennessee, 

 Little Pigeon R.), has greatly enlarged testes and appears to be near 

 spawning condition. No males of P. cymatotaenia collected in the 

 spring were examined, but a 69 mm. male taken on August 26 (UMMZ 

 152290, Mo., Gasconade R.) has slightly enlarged testes and a 

 well-developed caudal keel. The ventral scales of this specimen 

 have well developed ctenii, making the venter very rough to the touch. 

 The best-developed caudal keels I have observed were pointed out 

 to me by Reeve M. Bailey and are in three males of the undescribed 

 species of Hypohomus (UMMZ 165304, Kentucky, Green R., April 5, 

 50-65 mm.). They are covered with ctenoid scales resembling the 

 modified midventral scales usually present in males of Percina. 

 The anal fin of these males, considerably longer than that of the two 

 females in the same collection, reaches to the base of the caudal, 

 thus connecting it with the caudal keel and apparently forming a 

 single functional unit. 



Subgenus Alvordiiis Girard 



There are five species in this subgenus: macrocephala (Cope), 

 maculata (Girard), notogramma (Raney and Hubbs), pantherina 

 (Moore and Reeves), and peltata (Stauffer). I have examined ade- 

 quate breeding material of the last four species and have found no 

 tubercles. Males have enlarged midventral scales and considerably 

 more pigment in the first dorsal fin than the females have. Both sexes 

 of P. maculata are equal in size. The males lack breeding tubercles, 

 but the genital papillae of the females are elongate, broad, and tube- 

 like (Winn, 1958b, p. 172). Petravicz (1938) did not mention breed- 

 ing tubercles in this species. P. maculata spawns over sand or gravel, 

 with the male mounted on the female's back (Winn, 1958b, fig. 4). 

 P. peltata spawns in a similar manner, but the male's caudal peduncle 

 does not lie alongside the female's, as is the case of most darters. 

 The enlarged caducus scales on the male belly apparently serve both 

 to stimulate the female and to enable the male to maintain his position 

 over her (New, 1963; and pers. comm.). 



Subgenus Hadropteriis Agassiz 



There are three described species in this subgenus: nigrqfasciata 

 (Agassiz), sclera (Swain), and lenticula Richards and Knapp. There 

 are no tubercles on specimens taken in six March-April collections of 

 P. nigrofasciata from Georgia, Alabama, and Mississippi. The 

 ovaries and testes of these specimens are greatly enlarged, indicating 



