ACTINOPTERYGII. 121 



and extinct families ; but Sphyrcena itself, or a fish remarkably 

 like it, occurs as nearly complete skeletons in the Upper 

 Eocene of Monte Bolca, near Verona. 



Sub-Order 11. Percomorphi. 



The Berycoid fishes date from the Upper Cretaceous both 

 of Europe and America, but it is very doubtful whether any 

 existing genus occurs in the Chalk. The name Beryx, as 

 commonly applied to fossils, is very indefinite. Hoplopteryx 

 is a well-known extinct Cretaceous genus, differing from the 

 existing Beryx by the relatively great extent of its spinous 

 dorsal fin, which comprises six strong spines. H. lewesiensis 

 is a common species of the English Chalk, and the eight soft 

 rays besides the spine can be counted in the pelvic fin. 



The other Percomorphs are almost or exclusively Tertiary, 

 but many of the existing families are already differentiated in 

 the Eocene. The Scombridae are especially abundant, and 

 even so highly specialized a genus as the modern Remora 

 (Echeneis), with its remarkable sucker, has a representative in 

 the Upper Eocene (Lower Oligocene) of Canton Glarus with 

 a scarcely less developed sucker. The TrichiuridaB are also 

 represented in this formation by a fish indistinguishable from 

 Lepidopus. 



Sub-Order 12. Lophobranchii. 



Typical pipe-fishes occur in the Upper Eocene of Monte 

 Bolca and Monte Postale ; while a sea-horse (Calamostomd) 

 only differing from the existing Hippocampus in the possession 

 of a caudal fin, is also found in the quarries of Monte 

 Bolca. 



Sub-Order 13. Hemibranchii. 



Fistularia and Amphisyle, or fishes almost identical with 

 these, date from the Upper Eocene of Monte Bolca and Galicia, 

 and there is other evidence of Hemibranchs in the same forma- 

 tion. Unfortunately, all the specimens are much crushed. 



