101 



In Phoxinus, the anguloarticular is an irregular plate-like bone bearing an articular con- 

 cavity at its posteroventral portion, a posterior process at the posterior margin, and an an- 

 terior process at the anterior margin. The posterior process and the articular concavity of 

 the anguloarticular articulate with the quadrate. The posterior process of the anguloarti- 

 cular is well-developed and elongated in P. erythrogaster, tennesseensis, oreas, eos, cum- 

 berlandensis, phoxinus, and in the outgroups (TS 107[0]); the process is less developed, 

 and short in other species of Phoxinus (TS 107[1]). 



Meckel's Cartilage (Figs.59A, B, 60A-C, 61A-B). In cyprinids, the Meckel's cartilage 

 is a bar-shaped and partially ossified cartilage in adults; it is placed at the medial side of 

 the middle of the dentary, and the medial anterior portion of anguloarticular. The anterior 

 portion of the cartilage ossifies during ontogeny. This ossified portion, called mento- 

 mecklian, is continuous to the unossified cartilaginous portion and can not be separated 

 from the latter in Phoxinus. The shape of the Meckel's cartilage does not vary signifi- 

 cantly among Phoxinus species., However, the cartilaginous portion is reduced into a very 

 small part in P. brachyurus and erythrogaster (TS 108[ 1 ]): whereas it is not reduced in 

 other species of Phoxinus and in the outgroups (TS 108[0]). 



A 



Fig. 62: Urohyal of Phoxinus 

 (a, lateral, b, ventral and c, 

 dorsal views). A: P. neogaeus 

 (KU 8521, 53.0 mm SL); B: 

 P. brachyurus (MCZ 3006, 

 75.9 mm SL); C: P. tennes- 

 seensis (UT 44.5274. 50.0 

 mm SL). Scale bars = 1 mm. 



