72 U.S. NATIONAL MUSEUM BULLETIN 2 82, 



(mean 10.14). Pore counts of 192 canals from other areas show no 

 trend; the range is ten to twelve, and the average is 10.96. 



The number of vertebrae appear to be lowest in the west, especially 

 the Comite and Chefuncte drainages of Mississippi and Louisiana. 

 In this area the modes are 33 or 34 vertebrae. Elsewhere the modes 

 in the counts obtained are 35. The following summary lists in order 

 the number of specimens, range, and mean number of vertebrae for 

 each river system: Comite 11 (32-35) 33.6; Chefuncte 9 (33-35) 

 34.0; Pascagoula 8 (34-35) 34.6; Tombigbee 21 (35-37) 35.4; Alabama 

 15 (34-35) 34.7; Apalachicola 9 (34-36) 35.1; Savannah 20 (35-37) 

 35.3; Combahee 3 (35) 35.0; Edisto 3 (35-36) 35.3. 



The color pattern and body form are relatively uniform, and no 

 geographic trend is evident in the other tabulations. The number 

 of counts, the range (in parentheses), and the mean are given in 

 sequence for grouped samples from the following areas: (a) Lake 

 Pontchartrain drainage, (b) Pearl River drainage, (c) the area from 

 the Pascagoula River to the Tombigbee River, (d) Pensacola Bay 

 drainage, (e) the Apalachicola River to the Ochlockonee River, 



(f) Suwannee River drainage, (g) the area east of the Satilla River, 

 including the Great Cypress Swamp, and (h) the total. 



Anal rays: (a) 19 (16-17) 16.47; (b) 10 (15-16) 15.80; (c) 6 (15-16) 

 15.67; (d) 40 (15-18) 15.93; (e) 20 (14-17) 16.00; (f) 15 (14-17) 15.60; 



(g) 13 (15-19) 16.62; (h) 124 (14-19) 16.04. 



Lower-half caudal rays: (a) 11 (24-27) 24.91; (b) 10 (24-26) 25.30; 

 (c) 6 (23-27) 24.83; (d) 40 (23-28) 25.35; (e) 21 (22-28) 25.05; (f) 15 

 (24-27) 25.00; (g) 13 (23-27) 24.69; (h) 116 (22-28) 25.10. 



Upper-half caudal rays: (a) 11 (24-28) 25.64; (b) 10 (25-28) 26.80; 

 (c) 6 (23-26) 25.50; (d) 40 (24-30) 26.30; (e) 21 (24-29) 26.38; (f) 

 15 (25-29) 26.53; (g) 13 (24-27) 25.62; (h) 116 (23-30) 26.21. 



Total caudal rays: (a) 20 (48-57) 51.10; (b) 10 (50-54) 52.10; (c) 

 6 (47-56) 50.33; (d) 40 (48-58) 51.65; (e) 21 (47-57) 51.43; (f) 15 

 (50-54) 51.53; (g) 13 (48-53) 50.31; (h) 125 (47-58) 51.34. 



Distribution. — Noturus leptacanthus (map 3) occurs in both the 

 Atlantic and Gulf coastal drainages. It is found in most streams from 

 the Amite and Comite Rivers system of Louisiana and southwestern 

 Mississippi eastward to both the Great Cypress Swamp and Edisto 

 River, South Carolina. The Florida distribution, however, is poorly 

 known. Aside from a few uncertain records (included in the above 

 synonymy, but which perhaps refer to Noturus gyrinus), this species 

 is known to extend no farther into peninsular Florida than the Su- 

 wannee River system on the west and the Saint Johns basin in the 

 east. 



The distribution of A^. leptacanthus is strikingly similar to that of 

 Percina nigrofasciata as worked out by Crawford (1956, map 1). The 



