580 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



(Oligocephalus) nianguae are well developed on the anal elements 

 and, to a lesser degree, on the ventral surfaces of the pelvic rays. 

 Lack of tubercles may indicate that these two species are not as 

 closely related to P. evides as was indicated by Bailey (1940; and in 

 Bailey and Gosline, 1955). 



Subgenus Imostoma Jordan 



There are two species in this subgenus: shumardi (Girard) and 

 uranidea (Jordan and Gilbert). Males of both species have tubercles 

 on many areas and have the anal fin greatly elongated so that it 

 reaches to the caudal base. Bailey (1948) reported tubercles on the 

 lower fins of "the several species" of Imostoma. 



Tubercles are present on males of P. shumardi taken from January 

 12 (TU 14902, Mississippi, Pearl R.) to July 7 (USNM 44432, Indiana, 

 Wabash R.). At maximum development (USNM 187775, Texas, 

 Guadalupe R., Feb. 4, 47-56 mm.; UMMZ 81563, Michigan, Au 

 Sable R., April 30, 38-45 mm.; and KU 3208, Kansas, Neosho R., 

 April 10, 49-51 mm.) large high tubercles are present on the enth-e 

 length of the anal soft rays. Small tubercles are present on the second 

 anal spine. Tubercles are present on the entu'e length of the ventral 

 surface of pelvic soft rays 1-2 or 2-3 and on the distal tip of rays 3-4. 

 Tubercles cover the entire length of the most ventral five principal 

 rays of the caudal fin and a few are found on the distal tips of the next 

 two rays. Cross (1954) reported tubercles on the anal and caudal 

 fins of the KU specimens. In a 55 mm. male from USNM 187775, a 

 small tubercle is also present on the posterior portion of each of the 

 midventral scales, in addition to a few tubercles above the upper jaw 

 next to the openings of the infraorbital canal and a few scattered 

 tubercles on the posterior portions of the preopercle and opercle. 

 Tubercles are better developed on larger males as shown by TU 14902, 

 in which three males, 59-67 mm. long, lack tubercles and three males, 

 62-70 mm., have well-developed tubercles. Hubbs (1954) has noted 

 elongate tubercles on the anal rays of mature males. 



P. uranidea is even more tuberculate than P. shumardi, and is ex- 

 ceeded in the Percidae only by Romanichthys valsanicola and P. 

 (Ericosma) evides. At maximum tubercle development, males have 

 tubercles on almost all surfaces of the ventral half of the body (fig. 3). 

 The tubercles on the anal fin closely resemble those on P. shumardi 

 and are found at maximum development on the distal half to three- 

 fom"ths of all anal soft rays. Similar tubercles are present on the 

 ventral surface of all the elements of the pelvic fin, but they are larger 

 and better developed on the soft rays than on the spine. Although 

 they are also present on the dorsal surface, they are less numerous 



