GILL] THE TARPON AND LADY—FISH 33 
laries are very large, each composed of three pieces, and mostly 
outside of but adjoining the suborbitals (cor) ; the circumorbitals 
are peculiarly modified, there being a well developed preorbital, fol- 
lowed by a narrow suborbital, above the supramaxillary, and then 
by broad ones beginning above the hinder portion of the supra- 
maxillary and continued back of the orbits. The parasphenoid bone 
is narrow. 
The family of the Elopids, like that of the Chirocentrids, is a 
decadent one—one of the past rather than of the present. It was 
represented by numerous genera and still more numerous species 
during the Cretaceous epoch. Some of those were of large size, 
even exceeding the recent tarpon in dimensions, and almost all of 
them became extinct by the end of that period. The family was 
far less conspicuous during the Tertiary epoch, but as early as the 
Lower Eocene the still existing generic types Elops and Megalops 
made their appearance. At least remains of fishes found in the 
London Clay have been referred to these genera by A. Smith 
Woodward. Their later tertiary history is unknown. 
The living species are few in number—only four—and belong to 
two very distinct groups which are usually considered the only 
genera—Elops and Megalops. These are distinguishable by a num- 
ber of important characters. 
II 
i 
; ! 
7 ' 
} 1 
/ ! t 
P&P Lop SY g 
Fic. 3.—Elops saurus; hyopalatine arch, opercular bones, etc., with mandible ; 
left side, mesial aspect. j, jugular plate, dorsal view. (After Ridewood.) 
Elops, the genus which has given name to the family, has small 
scales, a small head, lower jaw not projecting, pseudobranchiz 
