98 



PH. GREENWOOD 



Fig. 4 Cheilodactylus fasciatus Medial aspect of left lower jaw, cheek region and hyoid arch. Scale = 2mm. 1: Anguloarticular-dentary 

 ligament; 2a: maxillary tendon of adductormandibulae muscle A,; 2b: extension of above tendon joining tendinous aponeurosis of adductor 

 mandibulae muscle Aw; 3: tendon of adductor mandibulae muscle Aw to preoperculum; 4: epihyal-interopercular ligament; 5a: extension 

 of tendon 3; 5b: branch of tendon 5a, attaching to quadrate above and interoperculum below; 6: interopercular-mandibular ligament; 7: 

 interhyal-quadrate ligament; x: anguloarticular-quadrate ligament. 



lus brachydactylus and Cheilodactylus pixi, have a 

 mandibular-preopercular-quadrate tendon system essentially 

 like that described above in Cheilodactylus fasciatus. In these 

 species the interopercular-quadrate branch (Fig. 4; 5b) does 

 not partly overlap that section of the complex (Fig. 4; 5a) 

 going to the anguloarticular. Instead, the two branches meet 

 in the same plane, with the result that the complex is clearly 

 single and 'Y'-shaped. Since the specimens of Chirodactylus 

 brachydactylus (standard length 106 mm) and Cheilodactylus 

 pixi (S.L. 70-81 mm) are much smaller than the specimen of 

 Cheilodactylus fasciatus (S.L. 243 mm), the difference could 

 be related either to the larger size of the C. fasciatus specimen 

 or to individual variation. 



The epihyal-interopercular ligament in Cheilodactylus is 

 short and broad (shorter even than that in the latrid Mendo- 

 soma; and unlike the long and anteriorly directed ligament in 

 the other latrid examined, Acantholatris, Fig. 4; lig. 4). As in 

 Acantholatris , but unlike Mendosoma, the interopercular 

 facet for the epihyal in Cheilodactylus is prominent and 

 well-developed (see Fig. 4). The interhyal-quadrate ligament 

 is long and flat (Fig. 4; lig. 7), again like that in Acantholatris, 

 but unlike its presumed homologue, the short and stout 

 interhyal-metapterygoid ligament in Mendosoma. 



The interhyal-preopercular ligament in Cheilodactylus is 

 also short and stout. No discrete interhyal-interopercular 



ligament is developed in the cheilodactylids, a characteristic 

 shared with the two latrid genera examined, but not with the 

 cirrhitid species studied. 



A stout anguloarticular-dentary ligament is present, as it is 

 in the other cirrhitoids, but unlike those taxa Cheilodactylus 

 has a short and broad ligament (x in Fig. 4) connecting the 

 uppermost part of the anguloarticular's posteromedial face to 

 the quadrate, where it is attached to the ventral rim of that 

 bone's facet for articulation with the anguloarticular. This 

 small ligament, not found in any of the other cirrhitoids 

 examined, is almost entirely hidden by tendon 5a of the 'Y' 

 shaped complex described above. 



A very stout interopercular-mandibular ligament originates 

 laterally on the dorsal margin of the interoperculum near its 

 anterior tip, and inserts mostly on the lateral aspect of the 

 anguloarticular and retroarticular bones, but with a short 

 medial branch going to the posteromedial face of the retroar- 

 ticular (6 in Fig. 4). 



DISCUSSION AND CONCLUSIONS 



The taxonomically and phylogenetically widespread occur- 



