96 MIOCENE FAUNA. 



the Swiss species (Murex truncutus) still occurs in tlie Mediterra- 

 nean and at the Senegal, and four others still live in the Medi- 

 terranean, which is also inhabited by one of the eleven Fusi of 

 the Molasse (Fusus rostratus, OL). Of the genus Cancellaria 

 eighty species are known, all being inhabitants of the tropics, 

 except one which is found in the Mediterranean and at Sene- 

 gambia. This species (C. cancellatd) lived formerly in the 

 Molassic sea ; but with it there were nine other species, one of 

 which (C. piscatoria) now occurs only in India. One of the 

 largest genera is Pleurotoma, of which 369 living and 305 fossil 

 species are known. It made its appearance as early as the Trias, 

 and has taken part in the population of the seas in all geological 

 ages. At present its chief seat is in the torrid zone, although 

 many small forms occur in the Mediterranean and even in the 

 north. These little forms are the last scanty remains of a 

 genus numerous species of which were formerly spread through 

 the European sea. The Swiss Molassic sea possessed twenty-two 

 species, only one of which (P. ramosa. Bast.) is found still living 

 at Senegambia. This species, like many other species of the 

 Molasse (such as P. gradata and granulato-cincta) had the shell 

 elegantly sculptured. Such sculpture is a still more striking 

 characteristic of the allied genus Cerithium, the turriform shells 

 of which are most beautifully adorned. Cerithium is a very large 

 genus ; commencing in the Trias, it attained its highest deve- 

 lopment in the Eocene period, and then diminished, although it 

 is still represented by 140 living species. The Cerithia live 

 chiefly at the mouths of rivers and in brackish water, where they 

 sometimes occur in immense quantities. They have already 

 been repeatedly mentioned. Eight species lived in the Molassic 

 sea; and of these, two (C. mediterraneum and scabrum) still occur 

 in the Mediterranean, and the latter also inhabits the North 

 Sea. Pyrula and Ficula are smaller genera of this family, in- 

 cluding tropical forms, which had a wide distribution in the 

 Miocene sea (such as Pyrula rusticola and Ficula clava and con- 

 dita). Two Tritonia also are types of the torrid zone ; whilst 

 of the two Ranella one (R. marginata, Mart.) inhabits West 

 Africa, and the other (R. scrobiculata ?) the Mediterranean. 



Of the Turbinacese six genera were represented in the Swiss 

 Molassic sea. Turbo and Trochus had been already met with in 



