418 REPORT ON ZOOLOGY, MDCCCXLIV. 



Alcide d'Orbigny is announced : Recherches sur les lois qui 

 president a la distribution geographique des Mollusques 

 raarins cotiers. The observations have reference only to 

 the coast of South America, and coincide with those which 

 the author had formerly published with respect to the 

 Foraminifera. (Yid. these Archiv. 1840, i, p. 398.) The 

 Falkland Islands have a special Fauna; that of the tem- 

 perate regions is richer than that of the torrid zone, and 

 this is the case in both oceans. Of 95 genera fifty belong 

 to one ocean outy, whilst 45 are common to both. The 

 currents tend to distribute those Molluscs which are capable 

 of enduring a more considerable variety of temperature. 

 Thus in the Atlantic Ocean 12 species are distributed over 

 19, and in the Pacific 15 species over 22 of latitude, and 

 cease on the northern limits of the currents. On the other 

 hand, the currents determine the line of separation of the 

 different Faunas, when they flow at a distance from the 

 coast, as at the Falkland Islands, or when they wash against 

 a promontory, as at Cape Horn, and when they flow impe- 

 tuously upon the coast, as near Payta. The temperature in 

 the next place constrains the species within narrower limits. 

 The oreographical conditions of the coasts have also an 

 important influence on the nature of the Fauna. 



For a review of the Mollusca of the North Sea, or at 

 least for a commencement of it, we are indebted to Menke. 

 (Zeitschrift, pp. 129-148.) There are three Cephalopoda, 

 seven Nudibranchia ; among which a new genus (vid. infra) 

 and a B-iilla. 



Essai sur les Mollusques terrestres et fluviatiles, et leurs 

 coquilles vivantes et fossiles, du departement du Gers, par 

 M. 1'Abbe D. Dupuy, Professeur d'Histoire Naturelle au 

 petit Seminaire d'Auch, Paris, 1843. 8vo. is known to me 

 only from the notice in the Rev. Zool. 1844, p. 189. 



From W. Thompson (Annals, xiii, p. 430) we have Addi- 

 tions to the Fauna of Ireland. In this list are enumerated 

 30 Gasteropoda, 2 Brachiopoda, 10 Lamellibranchiata, and 

 11 Tunicata. There are no new species among them. 



