130 
BUIylvETlN OF THE BUREAU OF FISHERIES. 
laterobasal comers prominent though rounded; basal lobe very large; Gila seems to be a very 
good genus, a fact of some importance, since if it were united to Richards onius, the name Gila would 
have priority. 
Hybognaihus Agassiz, silvery rahmovr. Proc. Biol. Soc. Wash., xxii, p. 122. Girard, Ichth. Mex. 
Boundary Survey, pi. xxvi, fig. 10-12 {H. serena)', pi. xxvi, fig. 14-16 {chrysitis=serena)\ pi. xxvi, 
fig. 22-24{texensis=episcopa)-, pi. xxvi, fig. 6-8 (argentosa—?episcopa)-, pi. xxvi, fig. 18-20 (me lanops); 
pi. XXVI, fig. 2-4 (couchi=melanops)-, pi. xxvii, fig. 18-20 (amara); pi. xxvii, fig. 14-16 (fluviatilis= 
amara). A member of the Pimephalinse, with scales of tlie type of Notropis, etc. 
Hybopsis Agassiz, horny-head. Proc. Biol. Soc. Wash., xxii, p. 162 (species of Hybopsis s. str., and the 
subgenera Erimystax Jordan, Yuriria Jordan & Evermann, and Macrhybobsis Cockerell & Allison). 
Girard, Ichth. Mex. Boundary Survey, p. 50, briefly describes the scales of H. mstivalis (Girard). 
Lavinia Girard. Proc. Biol. Soc. Wash., xxii, p. 161; Biological Bulletin, xx, pi. iv, fig. 23. 
Lepidomeda Cope. Proc. Biol. Soc. Wash., xxiv, p. 213. Scales transversely oval. 
Leuciscus auctt. Amer., dace= Richardsonius. 
Mylocheilus Agassiz, Columbia chub. Proc. Biol. Soc. Wash., xxiv, p. 213. The species there called 
M. caurinus (Richardson) is M. lateralis Agassiz & Pickering, caurinus auctt., not of Richardson. 
The species of Richardson is to be called Richardsonius caurinus. Mylocheilus lateralis often enters 
the sea. 
Myloleucus Cope. Proc. Biol. Soc. Wash., xxii, p. 161 (as Rutilus); xxii, p. 217. The aggregate 
called M. symmetricus is discussed in Biological Bulletin, xx, p. 374. 
Mylopharodon Ayres. The scales of immature M. conocephalus (Baird & Girard) from Merced River, 
California, are broad-oval, and except that they are considerably broader in proportion to their 
length, closely resemble in form and structure those of Orthodon microlepidotus; the pattern, 
with few (about 8) radii, all apical and widely spaced, and the interradial circuli very widely 
spaced, is exactly as in Orthodon. The base is broadly rounded, and there are no laterobasal angles. 
The fish has a large forked caudal; scales small; gill lamellie very obtuse; peritoneum marbled 
with light brown and speckled with black. Jordan & Evermann place this genus, with Mylocheilus 
and Stypodon, in a subfamily Mylopharodontinae, said to contain comparatively primitive forms, 
allied to those of Asia. The scales of Mylocheilus lateralis differ conspicuously from those of Mylo- 
pharodon, having the apical radii quite three times as numerous, and the sides nearly straight, 
with obtuse but evident laterobasal angles, the basal margin strongly convex in outline. Except 
for the absence of basal radii, they very greatly resemble the scales of Chondrostoma. It seems 
probable that Mylopharodontinae should be regarded as a tribe only (Mylopharodontini) of Chon- 
drostominse. 
Nocomis Girard. Proc. Biol. Soc. Wash., xxii, p. 161-162. The scale is formed and sculptured much 
after the manner of that of Richardsonius (Tigoma) pulchellus, but is much broader, with the vertical 
sides considerably shorter. (PI. xxxii, fig. 6.) 
Notemigonus Rafinesque, shiners. Proc. Biol. Soc. Wash., xxii, p. 211-213. Girard, Ichth. Mex. 
Boundary Survey, pi. xix, fig. 10-12 (as Luxilus leptosomus). On the same fish (from Falmouth, 
Mass.) the apical radii vary from 4 to 9; there are no traces of basal radii. The scales of N. chrys- 
oleucas (pi. xxxiii, fig. 8), first seen by me were immature; obtaining mature scales, I find that they 
are almost identical in form and sculpture with those of the European Abramis elongatus Agassiz, 
both being extremely different from those of A. brama, the type of Abramis. According to the 
scales, Ballerus should be much nearer to Notemigonus than to Abramis. Ballerus is, however, 
separable from N otemigonus by the teeth and fins. 
Notropis Rafinesque, minnows. Proc. Biol. Soc. Wash., xxii, p. 189-196; Biol. Bulletin, xx, pi. iv, 
fig. 25 (galacturus); Proc. Biol. Soc. Wash., xxii, p. 158, fig. 3 (cornutus)-, Girard, Ichth. Mex. 
Boundary Survey, figures N. lutrensis (complanata, couchi, gibbosa, rutila), proserpina (aurata), 
macrostomus (including luxiloides), texanus, venustus, swaini (megalops), amabilis, socius , frigidus , 
formosus, ornatus, and aztecus (vittata). Girard figures the scales of the two subgenera (Aztecula 
Jordan & Evermann and Codoma Girard) not studied by Cockerell & Calloway in 1909. Aztecula 
