15 



and erythrogaster with one row of pharyngeal teeth, but both bearing an incomplete body 

 lateral line. 



The fourth North American Phoxinus species, P. oreas, was described by Cope (1868) 

 from Roanoke of Montgomery County, Virginia, as Chrosomus oreas. This species re- 

 sembles Phoxinus eos (Cope 1868); the most obvious difference is in their coloration pat- 

 tern (Cope 1868). 



Jordan (1885) recognized two species under the genus Chrosomus: C. erythrogaster and 

 C. oreas, and stated C. eos identical to C. erythrogaster. In the same publication, Jordan 

 recognized 20 species under Phoxinus from North America which he split into six sub- 

 genera: Clinostomus, Tigoma, Siboma, Squalius, Cheonda, and Phoxinus. Most of these 

 subgenera were raised to genera by Jordan (1924). 



Jordan & Evermann (1896), in their four volumes of "The Fishes of North and Middle 

 America", considered Phoxinus as one of the eight subgenera included in Leuciscus. Three 

 species were assigned under the subgenus Phoxinus: P. neogaeus, margarita, and orcutti. 

 They listed three species under Chrosomus and pointed out that Chrosomus showed many 

 similarities with Phoxinus although none of the similarities were listed. 

 As in other fish groups, research on Phoxinus during these years focused mainly on the 

 description of new species and new records of geographical distribution. Detail morpho- 

 logical study was not yet conducted. 



1900-1919 



Smith (1908) studied the social spawning behavior of Phoxinus erythrogaster. This was 

 the first behavioral account of Phoxinus species. He also described the morphology of the 

 pearl organ (breeding tubercles) though the author did not recognize the breast tubercles 

 of the breeding males. Sexual dimorphism between the male and female of P. erythroga- 

 ster was shown by body color, relative size of pectoral fin, and "pearl organs" (Smith 

 1908). 



Cockerell & Callaway (1909) studied the scale morphology of some North American cy- 

 prinids and separated the subfamily Chondrostominae of Jordan & Evermann (1896) in- 

 to four subfamilies. Chrosomus was assigned in the subfamily Chrosominae. Cockerell & 

 Callaway (1909) considered Chrosomus a very primitive group which "might be an an- 

 cient offshoot from the stem which gave rise to Cyprinidae and Catostomidae." 

 Cockerell (1909) reviewed the nomenclature of North American fishes called "Leuciscus" 

 and "Rutilus". He demonstrated that the European "Leuciscus" and "Rutilus" differ from 

 the so-called "Leuciscus"- and "Rutilus "-species in North America. Cockerell also stu- 

 died the scales of Phoxinus and Chrosomus, and pointed out that the scales of both ge- 

 nera were of the same type, minute with radii in all fields. This was the first time that the 

 similarity between European Phoxinus and the North American Chrosomus was pointed 

 out. (Jordan & Evermann 1896 noticed the two "genera" were similar, but they did not 

 state what was the similarity the "genera" shared. See the above discussion.) 

 Following Cockerell (1909), Jordan (1916) demonstrated there was no true "Leuciscus"' 

 in North America and pointed out that the subgenus Phoxinus of Leuciscus needed to be 



