216 Cockerell — The Nomenclature of American Fishes. 



so strongly differentiated from lateral ones. The basal radii are 

 numerous and close together. (Gotha River, Sweden; Lloyd; 

 B. Mus.) 



(5) Id us Heck. 



L. idus (L. ). Scale of same general type as L. leucisciis, with the 

 same strong differentiation between lateral and apical circuli. 

 (Munio River, Lapland ; B. Mus. ) 



(()) Scardinius Bp. 



S. erythrophthalmus (L. ). Scale as in L. piyus, but even fewer 

 apical radii (four, widely spreading). Apical circuli same as 

 lateral. (River Cam, Newport; F. Templeman; B. Mus.) 



(7) Phoxinus Raf. 



P. phoxinus (L. ). Scale minute, broad, with radii all around; of 

 same type as those of Chrosomus and Tiaroga. (Merioneth; B. 

 Mus. ) 



The following is from North Africa: 

 (S) PhoxiveUns Heck. 



P. chaignoni (Vaillant) = callensis according to B. Mus. label. 

 Scale minute, broad, slightly triangular; circuli few; nuclear 

 area subbasal ; apical radii about ten, spreading; no basal radii: 

 lateral circuli about 18 to 20. (Oued el ]\Iahd; and Oued Abdal- 

 lah, Tunis; Paris Mus.; B. Mus.) These scales are extremely 

 > distinct from those of all the groups given above ; the resemblance 



to those of Phoxinus is merely superficial. 

 The Jai)anese L. jouyi and L. hakuensis are not closely related to (or, 

 apparently, even congeneric with) any of the above groups. Tliey show 

 a strong .approach to the American types. 



The American fishes, so far as known to me, may be arranged as follows : 



RiCHARDSONius Girard. (Leuciscus Auctt. Amer. ) 

 For table of species, see Proc. Biol. Soc. "Wash., XXII, \>. 159. 



(1) Subgenus Te meculina nov. 

 Scales of elongate type, with basal radii. 



Riciiardsonius orcutti (Eigenm. & Eigenm.). 



(2) Subgenus Tiogoma Girard. 



Richardsonius pulchellus (Baird and Girard); syn. Leuciscus nigres- 

 cens (Girard). 



Richardsonius pulchellus pandora (Cope). The northern subspecies. 

 I recently examined specimens of this form from San Luis Lake, 

 Costilla Co., Colorado (E. R. Warren), and was surprised to find 

 the peritoneum black, and the jiharyngeal teeth obtuse, scarcely 

 hooked. The intestine contained seeds. R. pulchellus is a curiously 

 variable species, such as one might imagine to arise from the inter- 

 mingling and hybridization of several species originally distinct. 



Richardsonius intermedius (Girard). 



Richardsonius alicix (Jouy). Atypical for this subgenus. 



