FOSSIL FISHES. 37 



The Alherinidce are represented at Monte Bolca by two very 

 small species of Atherina and by the genus Mesogaster. 



Mugilidce — " Grey Mullets." — Remains of the genus Mugil have 

 been found in the Tertiary deposits of Aix in Provence. 



The Fistulariidce — " Flute-mouths " — are well represented in the 

 Eocene formation. Fossil remains of the two living genera, Fistu- 

 loria and Aulostoma, occur at Monte Bolca and in the slates of the 

 Canton Glaris. 



Auh'scops, another existing form, has been found fossil at Padang, 

 in the Tertiary Lignites of the Island of Sumatra. 



Two extinct genera occur at Monte Bolca, Urosphen, the 

 cylindrical body of which is terminated by a large cuneiform fin ; 

 and JRhampliosus, which has an immense spinous ray, denticulated 

 behind, inserted on the nape. 



The Centriscidce — " Bellows-fish " — occur fossil in the Eocene 

 Tertiary strata of Monte Bolca, whence the genus AmpMsile is 

 recorded. 



The Pharyngognatiii have the lower pharyngeal bones united 

 and dentigerous. 



Lalridce — the " Wrasses " — have been found fossil in the Ter- 

 tiary formations of France, Germany, Italy and England, and 

 have been recognized by their united pharyngeal bones, which bear 

 molar-like teeth. 



The genus Labrus occurs at Monte Bolca, and in the Swiss 

 Molasse. JSTummopalatus and PhylJodus are allied forms, but can- 

 not be assigned to anv recent genus ; the latter first occurs in the 

 Cretaceous of Germany, and is not uncommon in the London Clay 

 of Sheppey, and by derivation in the Suffolk Crag. 



The Collection now contains nearly the whole of the British 

 specimens of PhyUodus and Egertonia figured in Prof. Cocchi's 

 Monograph on these fishes.* 



Taariniclitliys occurs in the Miocene of France; it represents the 

 living Odacina ; the genus Odonteus is found fossil at Monte Bolca, 

 whilst Egertonia, from the London Clay of Sheppey, differs in the 

 form of its palatal-like teeth from all recent genera of Labridce. 



The Axacanthini are a group of fishes in which the fins are 

 without spinous rays: there is no air-duct; the ventral fins are 

 jugular or thoracic. 



The GadidcB — " Cod-fishes "f — so abundant in the living state, 

 are rarely met with fossil. Two genera, Nemoptery$ and Palceogo- 

 dus, occur in the black slates of Glaris ; other forms occur allied to 

 Gadus, Merluccius, and PJiycis, in the London Clay of Sheppey, 

 and in the Miocene deposits of Licata in Sicily. 



The Phuronectida — "Flounders." — -The " Flat-fishes " are cha- 

 racterized, except in the very young state, by the peculiar habit of 

 constantly swimming aud resting upon one side, the forepart of 



* ' ' Monografia dei PharyngodopilidaV Florence, 1864. 



f This family also includes the "Hake," "Burbot," "Ling," "Rockling," 

 "Torsk," &c. 



