OBSERVATIONS ON FISH SCARES. 
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{N. aztecus) has scales which are narrower than those of most Notropis, with about 9 to ii apical 
radii. Codoma {N. ornatus), a fish remarkable for its vertical dark bands, has very ordinary scales 
of the Notropis type, the apieal radii 9 or 10. The subgeneric name Coccogenia Cockerell & Calloway 
gives way to the earlier and long-forgotten Coccotis Jordan, as Fowler has pointed out. Two new 
descriptions are added: 
Notropis lermcB Evermann &Goldsborough. Cotype; Lake Lerma, Mexico (J. N. Rose). Scales 
about 1.5 mm. long and 1.75 broad, rounded, not at all triangular, with 18-21 apical radii. 
Notropis horatii Cockerell. Type; Julesbiug, Colo. (H. G. Smith). Scales slightly over i mm. 
long and 1.5 broad, with rounded margins and 7 to 9 apical radii; circuli very widely spaced. 
Opsopceodus Hay. Proc. Biol. Soc. Wash., xxii, pi. m, fig. 3. Scale broader than long, with few radii. 
Orthodon Girard. Proc. Biol. Soc. Wash., xxn, p. 209-210, fig. i. Scale oval, longer than broad. 
Phenacobim Cope. Proc. Biol. Soc. Wash., xxii, p. 159; Biol. Bulletin, xx, pi. iv, fig. 24. Scale 
broader than long; radii few; apical circuli angulate in middle {P. mirabilis). In P. mirabilis the 
skin is thin, and the sculpture of the scales is clearly visible; in P. scopifer (from Longmont, Colo.) 
the skin is very thiek, and the sculpture of the scales is not visible until it is removed. 
Pimephales Rafinesque. Proc. Biol. Soc. Wash., xxii, p. 122; Biological Bulletin, xx, pi. v, fig. 26. 
Platygohio Gill, flathead chub. The scales of this genus have not been described, but I have examined 
a specimen of P. (Cope) from Salida, Colo., May, 1908 (Warren). There are 49 scales in 
the lateral line, covered by thick skin. Characteristic of the genus are the flatness of the head above 
and the falcate pectoral fins. Barbels distinct; gill filaments not fimbriate; peritoneum clear 
silvery. In the relatively large scales and small eyes it is like Nocomis rather than Couesius; the 
large vertically elongate nostrils are distinct from either, but rather nearer Couesim; the pigmenta- 
tion and tuberculate middle of head above resemble Couesius. Scales about 3 mm. long and 
4 broad, approximately semicireular, the basal outline gently convex, laterobasal comers distinet 
though obtuse; nucleus subbasal; cireuli crowded basally, rather widely spaced laterally; inter- 
radial circuli irregular and very widely spaced, more or less inelined to be angulate in middle, radii 
apical only, 11 or 12. The skin is densely very minutely tubercidate. 
Pogonichthys Girard, split-tail. Zoologischer Anzeiger, xxxvi, p. 479. An isolated genus in the Amer- 
ican fauna. Scales quite large, about 5)^ mm. long and 5 broad; nucleus about i }4 mm. from base; 
radii all apical, very numerous and close together, about 35; apical circuli not at all angled; latero- 
basal comers distinct; basal outline strongly convex. This is based on P. macrolepidotus (Ayres) 
from San Francisco (Dr. W. O. Ayres); the specimen in the British Museum, labeled Leucosomus 
incBquilobus . 
Ptychocheilus Agassiz, squawfish, Proc. Biol. Soc. Wash., xxn, p. 159, pi. in, fig. 2; Girard, Ichth. Mex. 
Boundary Survey, pi. xxxiv, fig. 2-4. Girard’s figxues show the more mature scales, in which the 
base is very distinctly produced. 
Rhinichthys Agassiz, black-nosed dace. Proc. Biol. Soc. Wash., xxn, p. 157. In R. cataractm dulcis 
from the Rio Grande in Colorado there are about 12 apieal radii and five distinet basal ones. In 
R. atronasus from Spring Creek, Tenn., I found about 20 apical radii, but the outermost of these 
strietly lateral; the basal radii were only imperfectly indicated. In most respeets the scales of 
dulcis and atronasus are essentially alike. This is closely related to Agosia {A. oscula, A. nubila), 
in which there are radii all around, the basal well developed. 
Richardsonius Girard. Proc. Biol. Soc. Wash., xxn, p. 159-160 (as Leuciscus)-, t. c., p. 216-217; t. c., 
p. 186, fig. I {pR. thermo philus); Biological Bulletin, xx, pi. n, fig. 14 {orcutti), pi. in, fig. 15 {pul- 
chellus), fig. 16 (carletoni), fig. 17 {thermophilus)-, Girard, lehth. Mex. Boundary Stuwey, pi. xxxiv, 
fig. 6-8 (pulchellus), pi. xxxni, fig. 2-4 (gibbosus), pi. xxxn, fig. 2-4 and 6-8 (nigrescens and pulchra= 
pulchellus). R. orcutti (Eigenmann & Eigenmann) is the type of the subgenus Temeculina Cockerell; 
R. pulchellus (Baird & Girard) represents the subgenus Tigoma Girard; R. thermophilus Evermann 
& Cockerell represents Richardsonius s. str.; R. carletoni (Kendall) is provisionally referred to 
subgenus Cheonda Girard. 
