48 U.S. NATIONAL MUSEUM BULLETIN 2 82 



than the general tone of the body. A dark gray axial streak is present ; 

 the lower body surface is variously unpigmented in young, lightly 

 or irregularly pigmented in older specimens. 



Variation. — The division of this species into eastern and western 

 subspecies or species as postulated by some authors (see synonymy), 

 does not appear to have foundation. It is a wide ranging species 

 that has some local differentiation, bvit which shows strong north 

 to south gradients. Some of these variations have been mentioned 

 above. 



Localized variation in the number of dorsal rays exists; gradients 

 in caudal, pelvic, pectoral, and possibly anal rays and preoperculo- 

 mandibular pores are evident. Specimens from northern glaciated 

 areas are heavy bodied and have relatively short spines; those from 

 more southern waters are emaciated and have long hard parts. No 

 trend in internasal pores is evident. 



The following summarizes in order the number of tabulations, 

 range (in parentheses), and mean for combined samples from (a) 

 Michigan, (b) New Jersey and New Hampshire, (c) North Carolina, 

 (d) Indiana, (e) southeastern Missouri, (f) Texas, (g) Black Warrior 

 River, (h) Florida, and (i) the total for all specimens. 



Lower-half caudal 7 ays: (a) 34 (22-25) 23.76; (b) 20 (22-28) 25.20; 

 (c) 4 (24-28) 26.00; (d) 29 (23-27) 25.03; (e) 30 (24-28) 26.20; (f) 



25 (23-29) 26.00; (g) 4 (26-29) 27.50; (h) 99 (25-32) 28.25; (i) 247 

 (22-32) 26.50. 



Upper-half caudal rays: (a) 34 (27-31) 29.44; (b) 21 (27-32) 29.67; 

 (c) 4 (28-31) 29.75; (d) 29 (28-34) 30.93; (e) 30 (28-34) 31.00; (f) 



26 (30-36) 32.15; (g) 4 (31-33) 32.25; (h) 100 (30-36) 32.75; (i) 250 

 (27-36) 31.48. 



Anal rays: Lake Huron drainage 52 (13-16) 14.65; Lake Erie 

 drainage 13 (14-16) 14.85; Lake Michigan drainage in lower Michigan 

 12 (13-16) 14.75; Michigan total 77 (13-16) 14.70; New Jersey 19 

 (15-17) 15.68; North Carolina 4 (16-17) 16.25; Indiana 30 (13-16) 

 14.73; Missouri 30 (12-16) 14.63; Texas 26 (13-17) 15.04; Florida 

 Parishes, Louisiana 2 (17-18) 17.50; Tombigbee River 14 (15-18) 

 16.36; peninsular Florida 103 (13-18) 15.50; and total 310 (12-18) 

 15.17. The other small samples fall in these ranges. 



Preoperculomandibular pores: Lake Huron drainage 136 (9-12) 

 10.23; Lake Erie drainage 48 (9-12) 10.42; Lake Michigan drainage 

 in lower Michigan 36 (10-11) 10.47; Michigan total 220 (9-12) 

 10.31; New Jersey 38 (8-11) 9.79; North Carolina 8 (10) 10.00; 

 Georgia 4 (10) 10.00; Indiana 62 (9-12) 10.21; Illinois 32 (10) 10.00; 

 Missouri 60 (10-11) 10.10; Oklahoma 34 (9-11) 10.03; Texas 108 

 (9-11) 10.04; Florida Parishes, Louisiana 4 (11) 11.00; other Louisiana 

 20 (9-11) 10.00; Mississippi drainage, Mississippi 12 (10-11) 10.17; 



