4 o 



ELOPIFORM FISHES 



n pu1 



nsppu2 



e P 1 -3 un3 



pu5 



c.sc 



5 mm 

 i 1 i 



Fig. 17. Anaethalion vidali (Sauvage). Caudal skeleton in left lateral view. Camera 

 lucida drawing of B.M.N. H. P.10375, partially restored. Arrows indicate upper and 

 lower principal fin-rays. 



There is also variation in the length of the second preural neural spine, long in 

 A. angustus, ' three-quarter length ' in A. (?) cf. subovatus and ' half-length ' in A. 

 angustissimus , A. knorri, A. gigas and A. sp. 



The three epurals of most species of Anaethalion form a graded series but those of 

 A. angustissimus are subequal in length, as in many primitive euteleostean fish. 



It is also to be noted that A . gigas from the Kimmeridgian of Spain shows a large 

 neural structure above the first preural and first ural centra. This appears to be a 

 result of fusion between two neural arches which in other species remain separate. 

 Such a fused structure may be a function of size. 



Regrettably, too few specimens were examined to allow an assessment of these 

 variations. The neural arches and spines are known to vary in Megalops (Text-fig. 

 33) and perhaps little attention is justified. The development of laminar bone in 

 some species may be of significance since this feature is usually associated with the 

 euteleostean caudal skeleton (Patterson 1970b). 



