148 U.S. NATIONAL MUSEUM BULLETIN 282 



fin often with a few brownish blotches; pectoral fin and membrane 

 over spine heavily pigmented, its edge immaculate; dorsal spine and 

 proximal part of dorsal fin brownish; remainder of dorsal fin often 

 with brown pigment distally on rays or some specimens with a dark 

 brown submarginal blotch or band; adipose fin whitish, the base 

 anteriorly with scattered brown pigment and the middle with a dark 

 brown or blackish blotch or bar which usually extends to the margin 

 in adults; this blotch confined to the upper body surface and discrete 

 from the other black saddles; another saddle extends from the front 

 of the adipose fin to a yellowish, obovate area at the base of the last 

 dorsal rays; a lightly pigmented area before the dorsal fin; a squarish 

 anterior saddle beginning just before the dorsal fin may extend to or 

 below the lateral line and backward to the third or fourth dorsal ray; 

 a yellowish white blotch on the upper and usually the lower procurrent 

 caudal rays, their base brown; a black or dark brown vertical bar 

 extends through the caudal peduncle to both margins of the caudal 

 fin; branched caudal rays and adjacent simple rays brownish or yellow- 

 ish brown with dark brown concentric bands at or near end of rays. 



Type.— The holotype (UMMZ 151171) is an adult male, 61.2 

 mm. in standard length and 73.5 mm. in total length. It has 5+9 = 14 

 anal rays, 17 + 6 + 10+14=47 caudal rays, 37 vertebrae, and 6 soft 

 dorsal rays. The pectoral fins and internasal pores are atypical, the 

 pectoral having eight soft rays on the left and nine (counting a small 

 splint) rays on the right; there is one internasal pore on the left and 

 two on the right side. On each side there are nine pelvic rays, seven 

 recurved serrations on the posterior edge of the pectoral spine, and 

 eleven preoperculomandibular pores. The head length stepped into 

 the standard length is 3.75 and the distance from the adipose notch 

 to the tip of the caudal fin stepped into the distance from the origin 

 of the dorsal fin to the adipose notch is 2.35 .The humeral process and 

 the anterior serrae of the pectoral spine are short or even obscure. 

 Plate 11, figure 2 shows the body form and pigmentation of this 

 specimen; table 28 gives further measurements. 



Distribution (map 10). — Noturus albater is known only from 

 the upper White and Saint Francis River systems of Arkansas and 

 Missouri. It occurs in the two main branches of the White, the Black 

 and the White Rivers and their tributaries. Two records are known 

 from the upper Saint Francis River, Missouri. 



Variation. — The meristic data taken from seven to ten specimens 

 from the Black River system are overlapped (one exception) by the 

 combined counts on 58 to 88 specimens from the upper White River 

 system. Means for the samples from (a) the White River, (b) the 

 Black River, and (c) the combined population follow in order: pelvic 

 rays (a) 9.04, (b) 8.95, (c) 9.03; soft pectoral rays (a) 8.94, (b) 8.85, 



