FOSSIL AND RECENT 37 



bone. Although the shape of the vomer could not be seen it is known to be a short 

 element bearing many small villiform teeth. Other species of Anaethalion examined 

 show a comparable development of the vomer and lateral ethmoid although most 

 appear to show some endochondral ossification of the mesethmoid. 



In all species of Anaethalion the parasphenoid is relatively narrow throughout 

 and is without a basipterygoid process. A. vidali differs from most species of the 

 genus, and also from Elops, in the shape of the parasphenoid. In A . vidali the para- 

 sphenoid is angled beneath the ascending wings. At this same level there are slight 

 lateral swellings. Both of these features are seen in the parasphenoid of megalopid 

 fishes and the shape of this element in A . vidali (Text-fig. 16, par) is most favourably 

 compared with that of Tarpon (Text-fig. 23, par). Small villiform teeth are borne 

 on the parasphenoid. 



Anaethalion vidali differs from other species of Anaethalion examined in having 

 the otic region of the neurocranial roof convex and the autosphenotic spine well 

 developed (Text-fig. 16, asp). 



The hyopalatine series is of the basic teleostean plan (Text-fig. 16). Unlike 

 Davichthys the metapterygoid is relatively shallow and thus more closely resembles 

 that seen in Elops. There is no evidence of an ectopterygoid process but the dorasl 

 margin of the ectopterygoid is slightly thickened. The quadrate/mandibular 

 articulation occurs beneath the posterior border of the eye, as in most other species 

 of Anaethalion, and is in a similar position in Davichthys lacostei (Arambourg 1954 : 

 fig. 28). In other species of Davichthys and Elops the articulation is situated more 

 posteriorly. A. angustissimus shows a condition similar to Elops. The backward 

 movement of the quadrate/mandibular articulation is a trend to be noted in the 

 Elopidae. 



The upper jaw of A. vidali is similar to that of other elopids, showing a small 

 premaxilla and small supramaxillae, the latter proportionately smaller than in 

 Elops and Davichthys. The palatine process on the maxilla is relatively small in 

 Anaethalion. Most species of Anaethalion (but not A . vidali) show a stout strengthen- 

 ing ridge upon the posterior supramaxilla, a feature which is interpreted as being the 

 primitive condition. 



The lower jaw is shallow as in other elopids and although other species of Anaetha- 

 lion show a variation in the depth and shape of the mandible (see Nybelin 1967b) 

 all show a weakly defined, posteriorly situated coronoid process, in contrast to lepto- 

 lepids. 



The anterior ceratohyal of all examined species of Anaethalion is fenestrated, un- 

 like that of Davichthys and Elops. A fenestrated ceratohyal is probably a primitive 

 feature since it is found in a great many primitive teleosts. ~ 



The circumorbital series of A . vidali is not known but there are minor differences 

 between other species of Anaethalion and Elops. The circumorbital series of several 

 species of Anaethalion has been described and figured by Nybelin (1967b) and Gau- 

 dant (1968). In those species of Anaethalion known in this respect the first infra- 

 orbital is ovoid, with a triangular antorbital resting directly upon its antero-dorsal 

 margin. There is no connection between the lachrymal and the supraorbital, and 

 the triradiate division of the infraorbital sensory canal (i.e. the origin of the antorbital 



