OBSERVATIONS ON FISH SCALES. 
155 
Hypohomus spilotus (Gilbert). Hector Creek, Ky. (Woolman). Scales known from those of Hadrop- 
terus by the very large number of basal radii. 
Cottogaster uranidea (Jordan & Gilbert). Vincennes, Ind. 
C. copelandi (Jordan). Iowandi, Ky. 
C. shumardi (Girard). Durkey’s Ferry, Wabash River, Ind.; also Wabash River, Ind. (Evermann). 
C. cheneyi Evermann & Kendall. Rackett River, N. Y. “Cotype.” This genus has small 
scales like those of Hadropterus, with the basal radii only moderately numerous (e. g., 9 or 10), 
but the scales are conspicuously broader than long, averaging considerably shorter than those 
of Hadropterus. 
Ulocentra stigmcea (Jordan). Obeys River, Olympus, Tenn. 
U. gilberti Evermann & Thobum. Walker’s Ford, Clinch River, Tenn. “Cotype.” 
U. meadice Jordan & Evermann. Indian Creek, Tenn. “Cotype.” 
U. histrio (Jordan & Gilbert). Black Rock, Rock River, Ark. 
U. simotera (Cope). Mount Verde, Tenn. 
U. “probably new.” Arnwine Creek, Athens, Tenn. 2inches long. 
Ulocentra has broad scales like those of Cottogaster, but the basal radii are more numerous (generally 
about 12), and the apical teeth are shorter, usually very short. U. stigmcea has very broad 
scales, some almost twice as broad as long, whereas in U. gil¬ 
berti they are mostly not greatly broader than long. 
Diplesion blennioides (Rafinesque), green-sided darter. Murfrees¬ 
boro, Tenn., 5 inches long. Scales xpi mm. long and broad, 
with long apical teeth and about a dozen basal radii. The 
scales are larger than those of Ulocentra, Cottogaster, etc., but so 
is the fish. I can not satisfactorily distinguish Diplesion scales 
from those of Percina. 
Boleosoma longimanus (Jordan). Lexington, Va. 
B. podostemone (Jordan & Jenkins). Roanoke River,Va. “ Cotype.” 
B. nigrum (Rafinesque). Osterville, Mass., and Columbia City, Ind. 
In this genus the scales are broader than long, with about a dozen basal radii. 
Crystallaria asprella (Jordan). Wabash River, Ind. 3 inches long; extremely small, rather broad 
scales, with long apical teeth. 
Ammocrypta pellucida (Baird), sand darter. Adamsboro, Ind. 3 inches long. 
A. beanii Jordan. Greenville, Ala. inches long. The scales of this genus are also extremely 
minute, almost rudimentary. 
loa vitrea (Cope). Raleigh, N. C. Scales minute, with long apical teeth; the principal character 
is found in the very widely spaced lateral circuli. The last three genera are the weakest scaled 
in the family. 
Etheostoma. In this large genus the scales are of the same type as those of related genera, with 
pigment spots along the bases of the apical teeth, such as are found in other American Etheo- 
stominae, in Zingel, and even in Acerina cernua. The basal radii vary from 9 (zonale, flabellare) 
to 16 (some pottsii, julice, and iowce). In some species the scales average about as broad as long 
(punctulatum), in others they are conspicuously broader than long ( julice, pottsii), but in no case 
are they longer than broad, if we take scales from the middle of the side and measure only to the 
bases of the apical teeth. In some the scales are comparatively large ( variatum ), in others 
very small ( flabellare ). After measuring what seemed to be fair average scales of each species, 
I have thrown my results into the following key, but it must be clearly understood that while 
it is indicative of general tendencies or types, it is not at all reliable for the determination of the 
species. 
Fig. 15. —Cottogaster shumardi (Per- 
cidae). Ctenoid structures. Bu¬ 
reau of Fisheries. 
