38 FOSSIL FISHES. 



the head, with both eyes, beconifng gradually twisted to the upper 

 or opposite side. 



" Flat-fishes " were not abundant in Tertiary times; the only 

 representatives being the genus Rhombus, from the Eocene of 

 Monte Bolca, and a small ; ' Sole" (Soled) from the Miocene near 

 Ulm in Wurtemberg. 



Physostomi. — The fishes of this division have all the fin-rays 

 articulated, only the first fin-ray of the dorsal and pectoral fins 

 being sometimes ossified. The ventral fins (if present) are 

 abdominal and without a spine. 



The Siluridce — " Cat-fishes." — A group of freshwater fishes 

 without scales, but in some genera the head and body are more or 

 less protected by dermal osseous scutes. 



The fossil representatives are Coccodus, from the Upper Chalk of 

 the Lebanon ; Silurus, from the Middle Eocene of Bracklesham, 

 and from some localities in France. Remains of undescribed 

 species from the Siwalik Hills, India, and from the highlands of 

 Padang, Sumatra, where the genera Pseudeutropius and JBayarius, 

 belonging to types common to India, have been found. Spines 

 referable to " Cat-fishes " occur also in the Tertiary deposits of 

 North America. 



The Scopelidce are exclusively marine pelagic or deep-sea fishes. 

 They are represented by Hemisaurida (allied to Saurus), from the 

 Chalk of Comen in Istria ; Parascopelus and Anapterus, from the 

 Miocene of Licata in Sicily. 



The Cyprinidce — the Carps, Goldfish, Tenches and Minnows — 

 belong to this family. Most of the fossil forms are referable to 

 existing genera. They occur in the Miocene Freshwater Limestone 

 of (Eaingen, and Steinheim ; in the lignites of Bonn, Stochen, 

 Bilin and Menat, also in the marl-slates of Licata in Sicily ; at 

 Idaho in North America, and Padaug in Sumatra. 



The genera represented are : — Barbus, Thynnichthys, Gobio, 

 Leuciscus, Tinea, Amblypharynyodon , Rhodeus, Cobifis, Acanthopsis, 

 Cyclurus, Ilexapsephus, and Mylocyprinus. Only a few exhibit 

 any characters by which they can be distinguished from living 

 forms. 



The Cyprinodontida arc a family of very small freshwater fishes, 

 most of the fossil species of which may be referred (in the opinion 

 of Dr. Guuther) to the living genus Cyprinodon. Lebias is found 

 in the Upper Eocene deposits of Aix in Provence ; in the Miocene 

 Limestone of CEningen ; the Brown Coal of Bonn, and in the 

 Marl of Gesso and St. Angelo. Roccilia also occurs at Giuingen. 



The remains of one species of Lebias (L. cephalotcs) are found 

 in shoals covering the surface of slabs of slaty marl at Aix in 

 Provence ; several good specimens of this may be seen in the 

 Cases. 



The Scombresocidce are a family composed chiefly of marine 

 fishes, some liviug in the open ocean, whilst others have become 

 acclimatized in freshwater ; the latter are viviparous, the former are 



