CLUPE1FORMES 



387 



ch. 



op 



remainder of the families; but it is very doubtful whether such 



a division is natural (p. 346). 



Ridewood has recently given an 



account of the skull of these fish 



[363]. 



Family ELOPIDAE. Both the 

 jnaxilla and premaxilla enter the 

 margin of the upper jaw. The 

 parietals meet in spite of the 

 junction below of the frontal with 

 the supraoccipital. The two supra- 

 temporals are large and meet (Elops) 

 (Fig. 326). It is remarkable that 

 the median gular plate is preserved 

 (Fig. 376), though often in a 

 vestigial condition. Small teeth 

 are present not only on the marginal 

 jaw-bones but also on all the bones 

 of the palate including the para- 

 sphenoid, and on the glossohyal 

 and pharyngeals. The eye-muscle 

 canal is present. There is a scapular 

 foramen, and three of the radials 

 rest on the coracoid. Usually there 

 are enlarged axillary scales (Fig. 

 376). 



Elops, L. (Fig. 377) ; tropical 

 seas ; Eocene, Europe. Megalops, 

 Lac. ; Tarpon, J. and E. ; S. 

 American Atlantic Coast, Indo- 

 iPacinc ; Eocene, Europe. Elopopsis, 

 Heckel ; Esocelops, A. S. W. ; 

 Europe ; Osmeroides, Ag. ; Europe, 

 Asia ; Notelops, A. S. W. ; Rhacolepis, Ag. ; S. America all Cretaceous. 



FIG. 37C. 



Head of Elops saurus, L. ; oblique ventral 

 view, a.sc, axillary scale ; b.r, branchiostegal 

 ray ; ch, preopercular region ; e, fold of skin 

 over eye ; g, lower jaw ; g.p, gular plate ; iop, 

 interopercular region ; mx, maxilla ; op, oper- 

 cular ; p.f, pectoral fin ; sop, subopercular. 



Fio. 377. 

 Elops saurus, L. (After Day, Fishes of India.) 



Family ALBULIDAE. This family dates from Cretaceous times like 



