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THE BLACK SEA. 



The Black Sea species are to the Mediterranean as 

 sixty to six hundred ; of these about thirty, or one- 

 half, are British. The Molluscous Fauna of the Black 

 Sea is Atlantic, and the assemblage of species, as 

 well as their relative frequency, causes it to resemble 

 the northern portion of the Lusitanian zone. The 

 species common to our seas and the Black Sea are 

 Cerithium adversum, Littorina rudis and neritoides, 

 Trochus umbilicatus, T. cinerarius, T. exiguus, Pha- 

 sianella pulla, Calyptrcea chinensis, Murex erinaceus, 

 JVassa reticulata and ascanias, Anomia ephippium, 

 Cardium edule and exiguum, Venerupis irus, Venus 

 aurea, V. gallina, V. dysera, Tellina tenuis, T. car- 

 naria, Mactra triangula, Solen ensis, Pholas Candida. 



The Lusitanian or Mediterranean species are, 

 Patella tarentina and ferruginea, three or four spe- 

 cies of Pissoa, Truncatella truncatula, Cerithium vul- 

 gatum, G. ferrugineum, Trochus divaricatus, T. Adan- 

 sonii, T. milieus, T. fragarioides, Pleurotoma costida- 

 tum, Tritonium corniculum, T. neriteum, Columbella 

 rustica, Conus Mediterraneus, Bulla striata. The 

 bivalves are Ostrea Adriatica, Pecten sulcatus, Myti- 

 lus minimus, M. latus, Lucina commutata, L. lactea, 

 Venus rudis, Mesodesma donacilla, Erycina ovata. 

 These two lists convey a very fair representation of 

 the assemblage of the Black Sea Mollusks. A few 

 more species might be added. All that are here 

 cited rest on the careful identifications of Dr. A. Yon 

 MiddendorfF, and the peculiarity of the assemblage 

 of marine species consists in the dwarfed size of in- 



