BULI^ETIN of The bureau op fisheries. 
156 
The following abbreviations are used: long., lat., length and breadth; ap., length of longer apical 
teeth; b. r., number of basal radii; measurements all in microns, except the length of the fish. 
A. Length of scale less than 800. 
a. Breadth of scale same as length. 
B.Jiabellare Rafinesque, fan-tailed darter (i inch). Cumberland Gap, Tenn.; long. 
and lat. 590; lateral radii very widely spaced; 9 b. r. 
E. punctulatum (Agassiz) (i inch). Marshfield, Ind.; long, and lat. 655; ap. 95; 
10 b. r. 
h. Breadth of scale much greater than length. 
I. Scale very broad; pigment spots along margin light brown. 
E. lepidum (Baird & Girard) (i>^ inch). New Braunfels, Tex.; long. 770, lat. 
1150; 12-14 t). r. 
ii. Scale moderately broad. 
E. australe Jordan. (i>^ inch). Chihuahua, Mexico; very widely spaced 
circuli around nucleus; long. 775, lat. 935; ap. 05; 12 b. r. 
E. camurum (Cope) blue-breasted darter (2^ inches). Marshland, Ind.; long. 
705, lat. 880; ap. 95; 10 b. r. 
E. tippecanoe Jordan & Evermann (2 inches). Marshland, Ind.; long. 750, 
lat. 865; 9-12 b. r. 
B. Length of scale 800 to 1,040. 
a. Scale about as broad as long. 
E. cragini Gilbert (i inch). Garden City, Kansas; “cotype”; long. 815, lat. 830; 
ap. 9s; 12 b. r. 
E. jessicE (Jordan & Brayton). Long. 1040, lat. 1055; ap. 145; 11-14 b. r. 
E. -whipplii (Girard). {i }4 inch). Kaimishi, I. T.; long, and lat. 800; lo-ii b. r. 
b. scale evidently broader than long. 
i. Basal radii 9. 
E. zonale (Cope) (i^ inch). Cumberland Gap, Tenn.; long. 990, lat. 1090. 
ii. Basal radii more than 10. 
E. iow(B Jordan & Meek. Creighton, Nebr.; long. 800, lat. 1040; ap. 80; 14-16 
b. r. 
E . obeyense Kirsch. inch) . Cumberland River, Wayne County, Ky. ; long. 
865, lat. 945; ap. 9s; 11-13 b. r. 
E. pottsii (Girard), inch). Chihuahua, Mexico; long. 960, lat. 1250; 15-16 
b. r. 
E. julicB Meek. Springfield, Mo.; long. 1040, lat. 1295; 13-16 b. r. 
E. boreale (Jordan) {2)4 inch). Michigamme, Mich.; long. 925, lat. 1010 
(another, long. 880, lat. 925); 12-14 b. r- 
C. length of scale over 1040. 
a. Length of scale 1490, breadth the same. 
E. variatum Kirtland (2 inches). Blue River, Wyandotte Cave, Ind.; ii b. r. 
b. Length of scale not over 1330. 
E. swannanoa Jordan & Evermann {ipi inch). Black Mountain, N. C.; long. 
1055, lat. 1280; 10-13 b. r. 
E. squamiceps Jordan inch). Murfreesboro, Tenn.; circuli around nucleus 
not very widely spaced; long. 1310, lat. 1375; ap. 72; 14 b. r. 
E.Jordawf Gilbert (2 inches). Oirford, Ala.; “cotype;” circuli aroxmd nucleus 
very widely spaced; long. 1170, lat. 1360; ap. no; 9-12 b. r. 
E. cinereum Storer (3)^ inches). Olympus, Tenn.; long. 1330, lat. 1345; ap. 
128; 12 b. r. 
E. coeruleum Storer, blue darter. (ip2 inch). Neosho, Mo.; long. 1120, lat. 1440; 
ap. 145; 11-15 b. r. 
E. rujilineatus (Cope) (2^ inches). Knoxville, Tenn.; long. 1150, lat. 1200; 
ap. 145; 13 b. r. 
It will be observed that there is very little correspondence between this arrangement and the sub- 
genera recognized by authors. It is certain that the scales are of very minor value in the taxonomy of 
this group, and no doubt individual variation oversteps most of the limits suggested by my data. At 
the same time there are good average differences between several of the species; thus, when we compare 
the species, E. pottsii and E. australe, both from Chihuahua, it is evident that pottsii has larger and 
broader scales, and the difference is greater than can be accounted for by the somewhat larger size of the 
fish. It is probable that if statistical studies are made of numerous scales, some help will be obtained 
for the separation of closely allied species. 
Psychromaster tuscumbia (Gilbert & Swain). Tuscumbia, Ala. Scales broader than long, not 
differing from those of Etheostoma. 
