126 



part (crest of neural complex - Cavender & Coburn 1992) is deeply grooved. It is nar- 

 row and relatively tall in P. phoxinus, erythro < gast er, brachyurus, neogaeus, and in the out- 

 groups (TS 176[0]): it is broad and relatively short in other species (TS 176[1]). In P. 

 phoxinus and eos, the grooved portion of the supraneural is narrower (TS 1 77[ 1 ] ) than 

 that in other species of Phoxinus and in the outgroups (TS 177[0]). In P. neogaeus, the 

 anterior portion of the dorsal margin of the supraneural is not grooved (TS 178[ 1] ). In 

 other species of Phoxinus and in the outgroups. its entire dorsal margin is grooved (TS 



The claustrum (Fig.77A-C, 79A-E) is located at the anterodorsal side of centrum 1. It co- 

 vers the atrium sinus impar ventromedially, and the anterior portion of scaphium poste- 

 riorly. It is roughly triangular on lateral view, and no variation with phylogenetic 

 significance was observed in Phoxinus. 



The scaphium (Figs 77A-C, 79A-E) is located posteriorly to the claustrum. Coburn (1982) 

 divided the scaphium into four parts: a cup at mesial, a posterodorsally directed spine, a 

 ventromedial articulating process, and a blunt tubercle posteriorly off the lateral surface 

 of the cup. Intraspecific variation is present in the morphology of different parts of the 

 bone in Phoxinus. For instance, in some specimens of P. phoxinus, a notch is present on 

 the margin of the cup: the notch is absent in other specimens of the same species; the po- 

 sterodorsal spine is sharp in some specimens, it is blunt in other specimens of the same 

 species. 



The intercalarium (Figs 77A-C. 79A-E. 80B) is a roughly T-shaped bone and placed at 

 the posterior to the scaphium anteriorly and anterior to the tripus. Via ligaments, the in- 

 tercalarium connects with scaphium and tripus posteriorly. The intercalarium can be divi- 

 ded into three parts, a dorsolateral process, a dorsomedial process, and a main part. 

 Generally, the dorsomedial process is shorter and blunter than the dorsolateral process. 

 The dorsal margin of the bone is deeply concave in P. neogaeus and oreas (TS 179[1]); 

 it is shallowly concave in other species of Phoxinus (TS 179[0]). The main part of the in- 

 tercalarium is slender and relatively long in P. erythrogaster (TS 1 80[ 1 ] ) ; it is broad and 

 relatively short in other species of Phoxinus (TS 180[0]). The medial and lateral spines 



178[0]) 



DLPI 



PR 



Fig. 80: Lateral view of tripus 

 (A) and intercalarium (B) of 

 Phoxinus erythrogaster (KU 

 5773. 51.5 mm SL). Scale bar 

 = 1 mm. 



