470 Miscellaneoi 



Species having that distribution were dredged by the ' Pola.' 



In this communication the Gastropoda, and, indeed (with the 

 exception of the Heteropoda and Pteropoda), the Scaphopoda and 

 Lamellibranchiata, are discussed. Of these groups there were 

 in all 120 species dredged. In the Mediterranean expedition 

 (I.-IV., 1890-93) there occurred 70 species (36 Gastropoda, 

 3 Scaphopoda, 37 Lamellibranchiata), in the Adriatic expedition 

 (1894) 63 species (36 Gastropoda, 2 Scaphopoda, 25 Lamellibran- 

 chiata) ; 19 species were found in both seas, 



In shnllow places more species were naturally dredged than in 

 deep ; so in every proportion of the fauna with regard to the vertical 

 distribution of species there must still be reckoned a considerable 

 decrease of species from above downwards. This decrease is a much 

 more striking one than in the western part of the Mediterranean, 

 and it would appear from this, and having regard to the fact that 

 on many stations at great depths the dredge yielded absolutely 

 nothing, that the conclusion is justified that the deeper parts of the 

 Eastern Mediterranean are still poorer than the analogous portions 

 of the western basin. 



The deepest part which still yielded molluscan shells was Station 

 no. 82, northward of Alexandria, 2120 metres. Here 9 species 

 were dredged, of which 5 were entirely new to science. One of 

 these species belonged to a new genus, which, from the horizontal 

 position of the hinge-teeth, was named Isorropodon. It is a shell 

 of inconsiderable size, with a maximum length of 11 millim. and 

 8'5 millim. in height, and from its external morphology might be 

 regarded as one of the Veneridne. The relations of the complicated 

 hinge point, however, to an affinity with Cypricardia liihophagella, 

 Lam. In a second new form from the same station the author 

 recognized a representative of the genus Myrina, which up to the 

 present is only known as coming from .North Australia and South 

 Africa. 



The sum total of new species amounted to 9 : they comprised 1 

 littoral of the genus Scalaria, 3 continental of the geuera Fusus, 

 Lyonsia, and Pecchiolia, and 5 abyssal of the genera Taranis, De- 

 franeia, Lucina, Isorropodon (new genus), and Myrina. 



12 species which up to the present have only been found in the 

 Western Mediterranean or in the Adriatic as the result of the 

 dredging by the ' Pola ' must now be regarded as having a distribu- 

 tion in the eastern basin. 



One of the species dredged by the ' Challenger ' expedition off the 

 Azores extends into the Mediterranean — Pleurotoma {Mangelia) 

 macro,, Watson. 



Two new varieties of RapJritoma nuperrima, Tib., form links with 

 Watson's species Pleurotoma (Mangelia) corallina and Pleurotoma 

 (Mangelia) acantJiodes from the West Indies and the Azores. 



Nine species, otherwise, it is true, already long known, are new 

 to the fauna of the Adriatic. — Sitzungsb. kais. Akad. der Wiss. 

 Wien, Jahrg. 1896, no. vii. pp. 56-59. 



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