574 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 



Tubercles are present along the outside of the pectoral fin on the 

 upper 10-11 rays and on the inside on the lower 2-6 rays. The 

 tubercles on the outer surface are longer and relatively low; those on 

 the inner surface are smaller and more conical. Tubercles are present 

 on the upper principal caudal rays, on the dorsal 3-4 rays of the lower 

 half of the caudal fin, and on the last three anal soft rays. Tubercles 

 are developed distally on all but the fii'st two dorsal spines and on the 

 entire length of the second dorsal rays. : This is the only percid with 

 tubercles on both dorsal fins. A low conical tubercle is present in the 

 center of most of the exposed body scales, although the tubercles are 

 smaller on the ventral side of the caudal peduncle. Tubercles also are 

 present on the dorsal half of the opercle. In many ways, the overall 

 appearance of the body tubercles on this specimen is reminiscent of the 

 tubercle pattern of the minnow Campostoma anomalum (see color 

 plate, Forbes and Richardson, 1909). One tuberculate female of R. 

 valsanicola (MCZ 40966) has small tubercles on many of the body 

 scales, the distal parts of the pectoral rays, the distal tip of pelvic soft 

 ray 4 (dorsal surface), and a few scattered tubercles on the upper 

 caudal fin rays. Another (UMMZ uncat.) has only a few poorly 

 developed tubercles on the pectoral rays. In the lengthy original 

 description of this genus and species (Dumitrescu, Banarescu, and 

 Stoica, 1957) there was no mention of breeding tubercles. 



Tribe Percini 



Genus Perca Linnaeus 



There is little sexual dimorphism m the three species of Perca: 

 flavescens (Mitchill), fluviatilis Linnaeus, and schrenki Kessler. I 

 have found no indication of breeding tubercles in sexually mature 

 specimens of P. flavescens or P. fluviatilis. There are no tubercles on 

 the single available male of P. schrenki (USNM 55712), which has 

 greatly enlarged testes. In P. flavescens of corresponding age, the 

 modal and average lengths of females exceed those of males (Hile and 

 Jobes, 1942; Beckman, 1949; Jobes, 1952). Females of P. fluviatilis 

 likewise are larger than males (Berg, 1949; Aim, 1952). Vladykov 

 (1931) and Oliva (1953) found that the paked fins of P. fluviatilis are 

 longer in males than in females. 



Genus Gymnocephalus Bloch 



There is sexual dimorphism in Gymnocephalus. Males of G. 

 cernua (Linnaeus) and G. schraetser (Linnaeus) are smaller than 

 females (Vladykov, 1931 ; Oliva, 1953) and the paired fins of the males 

 are somewhat longer. There are no tubercles on nine males of 



