326 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
lished in the Proceedings of the Academy of Natural Sciences of Phila- 
delphia (1854), and identifications of them have been carefully made by 
Alexander Agassiz (Proc. Boston Soc. Nat. Hist., 1861, 122). By this 
means the names given by Dr. Gibbons have taken their proper places 
in synonymy. 
The descriptions published by Dr. Ayres have, on the contrary, not 
been noticed, so far as I know, by any subsequent author, not even by 
Dr. Ayres himself, who soon after redescribed the same species as new, 
apparently not considering the first publication as a sufficient one, as 
one species at least received a new name on the second description. 
The following are the species in question : 
1. Leuciscus gibbosus Ayres. 
Stouter and thicker than any previously described species of the genus. Mouth 
small. About 60 scales in the lateral line. Brown above; silvery below. Weight 
about a pound. (Daily Placer Times and Transcript, issue of May 30, 1854.) 
This description is not very explicit, but we are to remember that the 
species was described from the fish market of San Francisco, and that 
the five species then common in the markets were the subjects of the 
five descriptions. The following species of Cyprinoid fishes are taken 
in the Lower Sacramento River, and are now, as then, abundant in the 
market of San Francisco: Ptychochilus oregonensis, Ptychochilus voraa, 
Siboma crassicauda, Pogonichthys inequilobus, Orthodon microlepidotus, 
and Catostomus occidentalis. 
The description of Leuciscus gibbosus above quoted, as well as a more 
elaborate one afterwards published of ‘ Lavinia gibbosa,” applies to 
Siboma crassicauda only among the fishes which come to the San Fran- 
cisco market. The name gibbosus was published in May, 1854; the name 
crassicauda in August, 1854. We have therefore no alternative but to 
drop ‘the latter very characteristic name, and call the species Siboma 
gibbosa, or, perhaps better, Telestes gibbosa, for the robust caudal pedun- 
cle hardly furnishes a sufficient reason for a genus Siboma. In Ayres’s 
time, as now, this species was known in the market as the ‘“¢ Chub.” 
2. Leuciscus microlepidotus Ayres (1. ¢., May 30). 
This species, afterwards more fully described as Gila microlepidota, is the well-known 
Orthodon microlepidotus. 
3. Leuciscus macrolepidotus Ayres (1. ¢., May 30). 
Form much like that of Leuciscus pulchellus, though a little more slender. Anal fin 
longer. Caudal much arcuated. Scales 60. Size of the preceding. 
This is evidently the species described in August of the same year by 
Baird and Girard as Pogonichthys inequilobus, under which name it was 
afterwards mentioned by Dr. Ayres. 
It must therefore take the less appropriate name of Pogonichthys ma- 
crolepidotus. This is now the “ Split-tail” of the markets. 
4, Leuciscus gracilus (sic) Ayres (1. ¢., May 30). 
Body slender; head much elongate. Color silvery, becoming darker on the back. 
Scales about 80; much larger than any other known Leuciscus, weighing, it is said, 30 
pounds or more, but generally varying, as we find it in the markets, from 5 to 20 
pounds. This is the species here known as Salmon Trout, &c. * * * 
