238 MM. Pictet and Humbert on the Fossil Fishes 



ralistj however, teaches us nothing more than his predecessors, 

 as he does not describe these fossils or discuss their zoological 

 affinities. De Blainville was the first to study scientifically some 

 of the Lebanon fishes. He described two species belonging to the 

 genus Clupea, and called them CI. Beurardi and CI. hrevissima. 



De Blainville's essay on the Ichthyolites was soon superseded 

 by the labours of Agassiz in 1833-1843. Nevertheless the 

 learned author of the 'Recherches sur les Poissons Fossiles' 

 possessed actually very slender materials relative to the fauna of 

 Lebanon. He brought to light four new species only, and added 

 some details respecting the two Clupea described by De Blainville. 



In 1845 Sir Philip Grey Egerton described a Ray from the 

 limestones of Hakel; and in 1849 Heckel made known four 

 or five species, brought from Syria by Th. Rotschy. In 1850 

 one of the present authors published a special memoir on the 

 fishes of the two deposits of Hakel and Sahel Alma, founded upon 

 important materials amassed by MM, E. Boissier and Blondel. 

 In this memoir twenty new species were described. 



Since this there has been only one work on the fishes of Le- 

 banon, that of M. 0. G. Costa, who has described and figured 

 four new species. 



Researches made in 1860 by one of the authors (A. Hum- 

 bert), in the deposits of the coast of Syria, have greatly enriched 

 the collection of the Museum of Geneva, both in new species 

 and in more perfect examples of such as had been previously 

 described. We have thought it advisable to pass in general 

 review the fishes of Lebanon, completing, whenever we could, 

 the descriptions of the forms already known, and inserting the 

 new species.' 



We here extract a portion of what we have said in our intro- 

 duction concerning the age of the two deposits as attested by 

 geological and palseontological evidence -, and we also reproduce 

 our general remarks on the two ichthyological faunas of Hakel 

 and Sahel Alma. 



Geological data. 



The beds which we have been considering are situated on the 

 eastern slope of Lebanon, between Tripoli and Beyrout, nearer, 

 however, to the last-named town. The nature of the rock and 

 the fauna of these two deposits" show that they belong to differ- 

 ent formations ; their age and relative antiquity have, however, 

 not yet been satisfactorily determined. 



MM. Agassiz and Heckel, in default of positive information, 

 have done no more than put forward certain hypotheses with 

 respect to the formation to which should be referred the few 

 species which they had within reach. 



