194 



Ridge in the Mississippi Embayment, and along the eastern rim of Mississippi floodplain 

 in Mississippi (Hemphill 1957), and near Reelfoot Lake, Tennessee (Starnes & Starnes 

 1980). These are considered the relic populations (Starnes & Starne 1980). In New Me- 

 xico and Colorado, isolated populations are present in the Arkansas River drainage (Kö- 

 ster 1957, Cross, pers. comm.). Starnes & Starnes (1980) summarized the distribution data 

 and prepared a map showing the geographical distribution of the species. 



Comments 



No subspecies of this widely distributed species has been reported. Some local and re- 

 gional intraspecific variation of the species was studied in Oklahoma by Hill & Jensen 

 (1969), and elsewhere by Phillips (1968a, 1969a). The intraspecific variation seems not 

 to be significant. 



Smith (1979) considered Oxygeneum pulverulentum Forbes a synonym of P. erythroga- 

 ster. However, O. pulverulentum is a hybrid of P. erythwgaster x Campostoma anomal - 

 um (Hubbs & Bailey 1952). 



Etymology 



The epithet erythwgaster is a Greek word, meaning "red belly" (Pflieger 1975), referring 

 to the ventral color of the breeding male. 



ABSTRACT 



Key Words: Cyprinidae, Phoxinus, Morphology, Osteology, Phylogeny, Taxonomy, Bio- 

 geography. 



Phoxinus is a small sized genus of Cyprinidae and occurs in both North America and Eu- 

 rasia. A detailed review on major literature related to Phoxinus showed that the definiti- 

 on, taxonomy, and composition of Phoxinus have changed since its first description by 

 Rafinesque (1820a), due to the unclear phylogenetic relationships among Phoxinus and 

 between Phoxinus and other minnow genera. 



The phylogenetic relationships of Phoxinus and other related minnow genera at the base 

 of the Chub clade were reevaluated based on 29 transformation series. The Hemitremian 

 clade was recognized as a monophyletic group and supported by the anterior placement 

 of the anterior anal pterygiophores. Eight genera are included in the Hemitremian clade, 

 i.e., Margariscus, Couesius, Semotilus, Hemitremia, Phoxinus, Eupallasella, Rhynchocy- 

 pris, and Lagowskiella, among which Hemitremia is the sistergroup of all other seven ge- 

 nera. 



The non-osteological and osteological morphology and their variations were described and 

 compared among Phoxinus, and between Phoxinus and the outgroups (i.e., Eupallasella, 

 Rhynchocypris, and Lagowskiella). The monophyly of Phoxinus was supported by eight 

 transformation series, such as the specific tuberculation on the breast scales in breeding 



