105 



Fig.65: Lateral view of the hyoid arch and basihyal of Phoxinus. A: P. neogaeus (KU 8521, 53.0 mm 

 SL): B: P. phoxinus (CNUc'uncat.. 76.0 mm TL); C: P. eos (KU 12255. 43.0 mm SL): D: P. cum- 

 berlandensis (KU 18934. 52.0 mm SL). Scale bars = 1 mm. 



cies of the Phoxinus and in the outgroups (TS 1 1 4[0] ). The anterior end of branchioste- 

 gal 3 is deeply concave in P. issykkulensis (TS 1 15[1]); the anterior end is not concave in 

 other species of the genus and in the outgroups (TS 1 15[0] ). 



Interhyal (Figs.64A-E, 65A-D). The interhyal is a small paired bone located at the most 

 posterior portion of the hyoid region. It articulates with the dorsal side of the posterior 

 ceratohyal, and ventral side of the hyomandibula dorsally via cartilage attaching on the 

 hyomandibula. No variation was found among Phoxinus species. 



Posterior Ceratohyal (Figs.64A-E, 65A-D). In Phoxinus, the posterior ceratohyal is a 

 triangular bone and articulates with the anterior ceratohyal anteriorly, and interhyal po- 

 sterodorsally. The dorsal side of the posterior ceratohyal bears a notch with which the in- 

 terhyal articulates. The bone is elongated triangular-shaped in P. neogaeus, issykkulensis, 

 brachyurus, and phoxinus (TS 116 [1]). whereas it is short triangular-shaped in other spe- 

 cies of Phoxinus (TS 116[0]) and in the outgroups. 



Anterior Ceratohyal (Figs.64A-E, 66A-D). The anterior ceratohyal is the largest ele- 

 ment in the hyoid region, and articulates with the ventral end of the posterior ceratohyal 

 posteriorly, and (the dorsal and ventral) hypohyals anteriorly. The anterior ceratohyal is 



