176 U.S. NATIONAL MUSEUM BULLETIN 2 82 



U (no number). Loosahatchie R., Hwy. 76, N. of Somerville, Fayette Co., 

 USNM 193463. 



Diagnosis. — Noturus (Rabida) stigmosus of the jurisous species 

 group has 47 to 56, usually 49 to 53 caudal rays; 13 to 16 anal rays; 

 8 to 10, normally 9 pelvic rays; 7 to 9, often 7, but more frequently 

 8 soft pectoral rays; and typically 2 internasal and 11 preoperculo- 

 mandibular pores. The posterior process of the cleithrum and spines 

 are long; the adipose fin is of moderate height. Other characters 

 contrasting it with members of the /i/riosMs group are: the blotch 

 of the adipose fin extends one-half to four-fifths the distance from the 

 base to the margin but not to the margin; the anterior abdominal 

 surface (except in large specimens) has many discrete chromatophores; 

 the anterior serrae of the pectoral spine are prominent; the adipose 

 and caudal fins are nearly free from each other; and the midcaudal 

 crescent typically extends across both the upper and lower procurrent 

 caudal rays to the caudal peduncle. 



The midcaudal crescent of pigment, the nearly separated caudal 

 and adipose fins, the eleven preoperculomandibular pores, and the 

 moderate number of caudal rays distinguish stigmosus from all 

 Noturus except species of the furiosus group. For further comparison 

 with members of the furiosus group, see table 14. 



Description. — Other counts and measurements are given in 

 tables 17 to 26. Body chunky, deepest below the dorsal fin; caudal 

 peduncle deep; head arched, slightly flattened above; lower jaw- 

 included; eye large, 1.7 to 2.4 times in snout; premaxillary tooth 

 patch with rounded or obtuse posterior corners; humeral process 

 longer than the width of pectoral spine and its serrae; pectoral spine 

 long, curved backward, with numerous, prominent dentations on the 

 anterior edge, and several on the posterior edge; posterior serrae, 

 except for the basal 1 to 3, with tips recurved toward spine base; 

 dorsal spine long, considerably longer than in Noturus eleutherus; 

 adipose fin of medium height, with a free posterior flap, and weakly 

 united at base to the short procurrent caudal rays; caudal fin truncate 

 behind, with rounded corners; gill rakers lour to seven on first arch. 

 The largest specimen examined is 100.5 mm. in standard length. 

 Many others are greater than 80 mm. 



Soft dorsal rays are five (in 5), six (129), and seven (11). Caudal 

 rays in Ohio Valley and Michigan specimens are (extremes in paren- 

 theses): (17) 18 to 20 (24), mean 19.8 upper simple rays; (14) 15 to 

 17 (19), mean 16.2 branched rays, of which (6) 7 (9) are in the upper 

 half and (7) 9 or 10 (11) are in the lower half of the fin; and (13) 14 

 to 16 (18), mean 15.1 lower simple rays; counts from western Tennessee 

 specimens fall within these ranges. Serrae on the posterior edge of 

 pectoral spine mostly 5 to 10, ranging up to 14. 



