6 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



dish; upper lip dusky ; scales little edged with darker; base of caudal 

 a little dusky. Head, 4 ; depth, 5^ ; scales, 6^38-4. 



17. Phenacobius mirabilis, Girard. 



{Exoglossiim miraMle, Girard, Proc. Ac. Nat. Sci. Phila., 1856, 191. 

 SarcicliHm scopiferuvi, Co-pe, Hayden's Kept. Geo!. Surv. Wyo., 1872, 440. 

 Flienacobius teretulus liosternus, Nelson, Ball. Ills. Lab. Nat. Hist., 1,1876,46.) 



Rather scarce, in the river. 



Very pale greenish, silvery below ; a silvery lateral stripe, rather dis- 

 tinct ; a conspicuous black spot at base of caudal, smaller than eye ; 

 fins, pale. Scales, 7-50-5 ; head, 4J ; depth, 4^. 



On comparing numerous specimens of Phenacobius mirabilis we find 

 two tyi)es which we at first took for two distinct species or varieties, but 

 which seem to intergrade fully. One of these {mirabilis) has the scales 

 comparatively small and with their outlines blended, not emphasized 

 by dark edgings. The following is the count of the scales : Des Moines 

 Eiver, 49, 50; Illinois Eiver, 50; Fort Smith, Arkansas, 52. Other 

 specimens {scopifer) from Illinois, Iowa, Missouri, Arkansas, Texas, «&c., 

 have scales larger, with dusky and therefore sharply defined edges ; 

 their numbers 43, 43, 44, 44, 44, 45, 45, 45 in eight specimens. There 

 is no other tangible difference, and we refer all to P. mirabilis. 



18. Hybopsis storerianus, Kirtlaud. 



(Eutilus siorerianus, Kirtland, Boston Journal Nat. Hist., 1, 71, 1842. 

 Hyhopsis storerianus, Girard, Proc. Ac. Nat. Sci. Phila., 1856, 211. 

 Ceratichthya lucens, Jordan, Proc. U. S. Nat. Mus., 1879, 238, not 

 Hyhopsis storerianus, Cope, Leuciscus storei'ianus, Giinther, or Cliola storeriana, 

 Jordan & Gilbert, which are Isotropis hudsonius amarus.) 



Very abundant in the current of the river ; next to N. tchipplei, the 

 most common fish in the river. 



The specimens called Hybopsis storerianus by Girard are still pre- 

 served in the National Museum. They belong to the species lately 

 described as Ceratichthys lucens, and we are now convinced that this is 

 the original storerianus of Dr. Kirtland. This species is far more widely 

 distributed and abundant in the West than has been hitherto supposed. 



Color in life, light olive above, bright silvery below ; scales above 

 with a few dark points along their edges ; sides with a bright silvery 

 band, above which is a green-stripe, which is visible in certain shades. 

 Sides with faint golden and bluish shades. Fins pale, the caudal dusky 

 at base, a little milky at tip. 



Teeth usually 1, 4-4,0, not 4-4. Barbel very conspicuous. Preorbital 

 bone large, silvery. 



19. Hybopsis hyostomus, Gilbert. 



A few small specimens found in the river. These agree with Gil- 

 bert's original types of Nocomis hyostomus. The "black parasitic 

 specks " mentioned by Professor Gilbert are found in all specimens of 

 this species, and are apparently permafient color markings, rather than 

 parasites. 



