CATFISH GENUS NOTURUS RAFESTESQUE 79 



formly dusky. Large specimens, above 90 mm., almost uniformly and 

 heavily pigmented over upper part of body, fins, and abdomen. 



Type. — Jordan and Gilbert (1886) listed Noturus nocturnus from 

 six localities in Oklahoma, Arkansas, and Texas, but based their 

 description on the specimens from Oklahoma and Arkansas. Their 

 specimens from the Rio Lampasas, Texas, are not nocturnus but are 

 Noturus gynnus. Two of the localities have been variously listed (see 

 synonymy) as the type-locality, beginning with Evermann and 

 Kendall (1894). Evermann and Kendall were the first to publish a 

 figure of nocturnus, based on a specimen from the Saline River, 

 Benton, Arkansas. This figure was reprinted by Jordan and Ever- 

 mann (1900, p. 3236, pi. 27, fig. 64) and stated to be from the type, 

 USNM 36461, essentially designating a lectotype. 



When examined by me, USNM 36461 contained three specimens in 

 agreement with the original catalog record. The largest of the three 

 is herein selected as the lectotype because it most closely approaches 

 the length of 2.3 inches noted on the drawing and is unique in having 

 a dark longitudinal line near the middle of the caudal fin, as shown 

 on the original drawing and many of the published illustrations. The 

 lectotype retains the number USNM 36461. 



The lectotype is a male, 48.5 mm. in standard length. It has 18 

 anal rays, 26+8 + 11 + 17=62 caudal rays, and 6 soft dorsal rays. 

 On each side there are nine pelvic rays, nine soft pectoral rays, two 

 internasal pores, and eleven preoperculomandibular pores. The poste- 

 rior edge of the pectoral spine is roughened, Nvithout serrae. The head 

 length is stepped into the standard length 3.8 times and the distance 

 from the adipose notch to the tip of the caudal fin is stepped into the 

 distance from the origin of the dorsal fin to the adipose notch 1.55 

 times. 



Variation. — Noturus nocturnus is a variable species and appears to 

 form distinctive localized populations. The most noteworthy of these is 

 one in the Red River S3'stem. There, specimens are often light gray to 

 yellowish and sometimes have extremely short spines. In this system 

 the preoperculomandibular pores are often ten instead of eleven. 

 Some Texas specimens are extremely elongate, but show no increase 

 in meristic characters. The single specimen from the Tennessee basin 

 in Mississippi has 20 anal rays, an unusually high number. Color 

 variations are a prominent brownish band near the edge of the anal 

 fin and a rather broad white posterior margin of the caudal fin, but 

 there is no definite geographic trend. The specimens from the Alabama 

 River have a high number of soft pectoral rays, modally ten; other 

 specimens from eastern Gulf tributaries tend to have a higher number 

 of pectoral rays than elsewhere. 



