29 



organ. In Rhynchocypris and Lagowskiella, the dorsal margin of the primary lamellae bears 

 a deep notch (Fig.5B); in the outgroups and other genera of the ingroups, the margin does 

 not bear the deep notch (Fig. 5 A). - TS 3: A deep notch absent [0] or present [1] on the 

 dorsal margin of the primary lamellae in the olfactory organ. 



4. Supraorbital sensory canal (Fig.6A-D). The supraorbital sensory canal runs from the 

 parietal posteriorly to the nasal bone anteriorly. It is interrupted into two portions, though 

 the range of the gap might vary, between the anterior end of the frontal bone and the po- 

 sterior end of the nasal bone in Phoxinus (Fig.6D). The canal is not interrupted at this re- 

 gion in other members of the ingroups and in the outgroups (Fig.6A-C). However, the 

 interrupted canal is also found in Cyprinus and Gila of Cyprinidae (Cavender & Coburn 

 1992). - TS 4: Supraorbital sensory canal not interrupted [0], or interrupted [1] between 

 the anterior end of the frontal bone and the posterior end of the nasal bone. 



5. Supratemporal sensory canal (Fig.7A-C). In the outgroups, in Rhynchocypris and Se- 

 motilus, the left and right portions of the supratemporal sensory canal connect on the pa- 

 rietal (Fig.7A-B). Therefore, the supratemporal canal is continuous between the left and 

 right portions of the canal. In other members of the ingroup, however, the canal is inter- 

 rupted on the parietal. - TS 5: Left and right supratemporal sensory canals connect [0], 

 or not connect [1] each other on the parietal. 



6. Preopercular sensory canal (Fig. 8 A-C). In the outgroups, in Hemitremia, Rhynchocy- 

 pris, Lagowskiella, Margariscus, Eupallasella, and in Semotilus, the preopercular sensory 

 canal extends upward and terminates at or near to the tip of the ascending arm of the 

 preopercle bone (Fig.8A-B). In Phoxinus and Couesius, the preopercular canal terminates 

 at about the middle of the ascending arm of the bone (Fig.8C). 



Coburn & Cavender (1992) considered the "shortened preopercular canal" an evidence 

 supporting the relationship of Phoxinus and other genera of the Chub clade. However, the 



Fig. 8: Preopercular canal (in 

 black) and preopercle in he- 

 mitremians and in the out- 

 group. A: Nocomis 

 platyrhynchus (KU 18926, 

 46.5 mm SL); B: Semotilus 

 corporate (KU 18856. 58.0 

 mm SL): C: Phoxinus 

 erythrogaster (KU 5773. 62.0 

 mm SL). Scale bars = 1 mm. 



