Ill 



geminal nerve passes through the notch (Arratia & Schultze 1991). Variations of the me- 

 tapterygoid include the relative position of the two articular surfaces at the posterior 

 margin, and shape of the two processes. 



The two articular surfaces at the posterior margin of the metapterygoid are well-develo- 

 ped and close to each other in P. eos, brachyurus, issykkulensis, erythro gaster, and pho- 

 xinus (TS 131[1]). In other species of Phoxinus and in the outgroups, the two surfaces are 

 less developed (TS 131 [0]). 



The notch at the dorsal margin of the metapterygoid is deep in P. brachyurus, phoxinus, 

 and in the outgroups (TS 132[0]); it is relatively shallow in other species (TS 132[1]). 

 The processus basalis of the metapterygoid is narrow and high in P. erythrogaster, pho- 

 xinus, issykkulensis, cumberlandensis, and in the outgroups (TS 133[0]); the process is 

 broad and relatively lower in other species of Phoxinus (TS 133[1]). 

 Hyomandibular (Figs.69A-C, 70A-F). In cyprinids, the hyomandibular is an en- 

 dochondral bone and is placed at the posterior portion of the viscerocranium. The dorsal 



Fig. 70: Lateral view of hyo- 

 mandibula of Phoxinus. A: P. 

 phoxinus (CNUC uncat.. TL 

 76.0 mm); B: P. neogaeus 

 (KU 8521, 53.0 mm SL); C: 

 P. oreas (KU 3259, 55.0 mm 

 SL); D: P. erythrogaster (KU 

 5773, 51.5 mm SL); E: P. 

 brachyurus (MCZ 3006, 75.9 

 mm SL); F: P. tennesseensis 

 (UT 44.5274, 50.0 mm SL). 

 Scale bars = 1 mm. 



