34 



13. Frontal bone (Fig.6A-D). In Hemitremia. the anterolateral margin of the frontal bone 

 bears a deep notch articulating with the supraorbital bone (Fig.6B): the lateral margin of 

 the frontal does not bear the deep notch in other members of the ingroup and in the out- 

 groups (Fig.öA. CD). - TS 15: The anterolateral margin of the frontal articulating with 

 supraorbital bone not forming a deep notch [0]. or forming a deep notch [1]. 



14. Orbital septum (Fig.l2A-E). The orbital septum is formed by fusion of the base of 

 the left and right orbitosphenoids. An anterior process is present at the anterior margin of 

 the orbital septum. The process is absent in outgroups and most members of the ingroups 

 i Fig. 12 A. B. E): the process is present in Semotilus, Hemitremia. and Eupallcisella 

 (Fig.l2C-D). 



The orbital septum is high in most members of the ingroup and in the outgroups (Fig.l2B- 

 C). but lower in Lagowskiella. Phoxinus. and Couesius (Fig.l2A. E). 

 In Semotilus. Hemitremia. Phoxinus. Margariscus. and in the outgroups. the orbital sep- 

 tum narrowly joins the dorsal side of the parasphenoid (Fig.l2C, D-E); in other members 

 of the ingroup. the septum broadly joins the parasphenoid < Fig. 12A-B ». 



In most members of the ingroup and in the outgroups. no cartilage is present in front of 

 the orbital septum in adult individuals (Tig.l2A-B. D-Ei: in Hemitremia and Eupallasel- 

 la. a short bar-shaped cartilage is present in front of the orbital septum (Fig.l2C). 



TS 16: An anterior process at the anterior margin of the orbital septum absent [0]. or pre- 

 sent [1]. - TS 17: Orbital septum high [0]. or lower [1]. - TS 18: Orbital septum narrow- 

 ly [0]. or widely connecting with the dorsal side of the parasphenoid [1]. - TS 19: A 

 cartilage absent [0]. or present [1] in front of the orbital septum in adults. 



15. Supraorbital bone. In Hemitremia. Lagowshiella. and in the outgroups. the supraorbi- 

 tal bone is large and well-developed: in other genera of the ingroup. the supraorbital bo- 

 ne is reduced to a narrow and short one. 



Howes C1985) proposed presence of the small supraorbital bone as one of the synapo- 

 morphies of Phoxinus. My study shows that this character is widely distributed in sever- 

 al genera of Hemitremians. - TS 20: Supraorbital bone large [0]. or small [1]. 



16. Basioccipital bone (Fig.l3A-C). In Phoxinus. Rhynchocypris. Campostoma. Dionda. 

 and Hybognathus. the pharyngeal pad of the basioccipital bone bears an anterior process 

 i Fig. 1 3d i also see Mayden 1989. Schmidt 1989 1. In other members of the outgroups and 

 ingroups. this process is absent (Fig.l3Bi. However, in P. neogaeus and P. brachyurus. 

 the process is absent as well. The absence of this anterior process in these two species is 

 interpreted as a reversal of its presence, an apomorphy of these two species isee page 94 

 for the related discussion). - TS 21: The anterior process of the pharyngeal pad of the 

 basioccipital bone absent [0]. or present [1]. 



17. Parasphenoid bone (Fig.l3D-E). The anterior pan (in front of the ascending wing) of 

 the parasphenoid in Hemitremians is dorsally bent. The angle a (Fig.l3A) is herein defi- 

 ned as the angle between the horizontal line extending from the ventral side of the po- 

 sterior part (posterior to the ascending wing) of the parasphenoid and the ventral side of 

 the anterior pan of the bone (anterior to the ascending wing). The larger this angle is. the 

 greater the bent in the anterior part of the parasphenoid (Fig. 1 3D). In Hemitremia and in 



