^0 Prof. E. Suess on the former Connexion 



desert still lie far below the level of the sea, and that the wide- 

 spread saline incrustations have from the remotest times been 

 regarded as proofs of a former overflow of the sea. 

 . With the progress of Hornes's investigations, indications of 

 the accuracy of this conclusion have increased. Not only have 

 ■we become acquainted with several species of bivalves whose 

 present distribution extends as far as the Senegal, such as Lu- 

 traria ohlonga, Tellina crassa, T. lacunosa, Venus ovata, and three 

 of our four species of Artemis, namely, A. exoieta, A. lincta, and 

 A. Adansoni, but we now meet in our basin with some of the most 

 prominent of Adanson^s types, which at present are only to be 

 found living on the coast of Senegambia, namely, Adanson's 

 ''Tugon" {Tugonia anatina) and "Vagal" [Tellina strigosa) : 

 the great Mactra Bucklandi, also, no longer living on European 

 shores, is met with still at the Senegal. All accounts of the 

 desert, however, agree so closely with the supposition of an 

 overflowing, that, independently of these palseontological indi- 

 cations, other observers as well as Laurent were led to it solely 

 by the form and constitution of the soil. Barth appears to 

 have kept to the old Roman road between Tripoli and Mourzuk, 

 almost always beyond the easterly margin of this ancient sea ; 

 and it would not be uninteresting to ascertain how far the out- 

 lines of this sea agree with Duveyrier's account of the boundaries 

 of the land. 



The present land-fauna of Morocco and Algeria, as far as 

 Cyrenaica, agrees at the present time in its most essential 

 points entirely with that of South Europe — on the one hand 

 with that of the Pyrenean peninsula, and on the other with 

 that of South Italy ; whilst on the Senegal and Gambia, and the 

 other successive regions beyond the desert, as far as the Nile, 

 only the true African type appears. The elephant, rhinoceros, 

 hippopotamus, giraffe, crocodile, and many other important 

 members of the African fauna do not extend beyond the Sahara ; 

 and the contrast of this Morocco-Algerian land-fauna is very 

 remarkable, as opposed to the true African fauna in most classes 

 of animals, whilst the connecting links with Europe are not to 

 be mistaken. 



Moritz "Wagner's ' Journey in the Kingdom of Algeria' con- 

 tains numerous proofs of this, and they increase with every 

 comparison. The extension of the Inuus ecaudatus to Gibraltar 

 is well known. The Sorex etruscus, an otherwise exclusively 

 Italian animal, is met with in Algiers. The fox, paler in 

 Italy than in Germany, appears in Algeria as a still lighter 

 variety. Of greater value for these investigations is the distri- 

 bution of reptiles, as they are very little influenced by man ; and 

 it may be mentioned that the new ' Algerian Herpetology ' of 



