GILBERT: FISHES OF THE SUBGENUS LUXILUS


 Baird). Cope, 1864: 279 (spelling emended to Hypsilepis). Jordan, 1876b:
 283 (Hypsilepis synonymized with Luxilus). Jordan and Copeland, 1876: 153
 (Hypsilepis synonymized with Luxilus).
Plargyrus Rafinesque, 1820a: 50-51 (substitute name for Rutilus if included spe-
 cies are not in that genus; type species, by absolute tautonymy, Rutilus plar-
 gyrus). Kirtland, 1845: 26 (refers to species Leuciscus plargyrus). Storer,
 1846: 158 (refers to species Leuciscus plargyrus). Girard, 1856: 196 (Plar-
 gyrus accorded generic status). Jordan, 1876a: 94 (Rutilus plargyrus Rafines-
 que wrongly synonymized with Luxilus kentuckiensis). Jordan, 1876b: 281
 (incorrectly allied with part of present subgenus Cyprinella). Jordan, 1877:
 28-29 (Plargyrus Girard [not of Rafinesque] placed in synonymy of Luxilus;
 review of Rafinesque's species).
Coccotis Jordan, 1882: 852 (proposed as a subgenus of Luxilus; type species,
 by original designation, Luxilus coccogenis). Jordan, Evermann and Clark,
 1930: 127 (generic status).

Coccogenia Cockerell and Callaway, 1909: 190-191 (proposed as a subgenus of
 Notropis on basis of scale characters; type species by original designation,
 Notropis coccogenis).

 The genus Notropis Rafinesque (1818) is a large and diverse group,
containing numerous closely related, morphologically similar forms.
At various times in the past its principal components have been re-
garded as distinct, though poorly-defined genera. Gilbert (1884b)
was the first to propose that a number of these be combined under
the name Notropis. Jordan (1885b) relegated these groups to sub-
generic status within the broad genus Notropis, where they have
remained ever since despite sporadic efforts (Jordan, 1929; Jordan,
Evermann and Clark, 1930) to separate them.
 Although some of the chief subgroups of Notropis are difficult to
separate and the relationships of some are not yet clear, several
clusters of species share morphological characters and obviously con-
stitute natural units. The subgenus Luxilus Rafinesque (1820a) is one
such group. The species of Luxilus are characterized by common
diagnostic features, but the diversity of their past assignment to
genera shows that ichthyologists have not always recognized their
close interrelationship. Some have been moved indiscriminantly
from group to group without apparent reason.
 Part of the difficulty regarding the status of Luxilus stems from
the original description (Rafinesque, 1820a: 47-48) which, as is often
true of Rafinesque's accounts, is quite general and vague. Of the
four species he included in this group, only one (L. chrysocephalus)
is now assigned to Luxilus as presently defined.


1964