384 MANUAL OF THE MOLLUSCA. 



Limncea invohita have only been met with in the south-west of Irelaiidy hni 

 are possibly Lusitauian species, Dreissena poJi/morpha has been permanently 

 naturalized in canals (p. 267), and Testacella Maugei and haliotldea iu 

 gardens; Bnlimus decollatus and Goodalli have been often established in 

 gi*eenhouses. Some species are now very scarce in England that were formerly 

 abundant, as : — 



Clausilia plicatula. Vertigo Venetzii. Succinea oblonga. 



Vertigo minutissima. Helix lamellata. Acicula fusca. 



Others which occttr in the newer tertiary deposits have become quite 

 extinct in England, such as : — 



Helix fruticum, living in France and Sweden. 



„ ruderata Germany. 



„ labyrinthica (Eocene) New England. 



Paludina marginata France. 



Corbicula consobrina Egypt and India. 



Unio litoralis France and Spain. 



On the other hand, some of the commonest living species have not been 

 found fossil; e.g. Helix asperSa, pomatia, and cantlana. Several genera only 

 occur fossil in the older tertiaries, viz. : — 



Glaudina. Cyclotus. Neinatura. 



Pro3ei-})ina. Megalomagtoma. Melauia. 



Cylindrella ? Ci-aspedoporua. Melanopsis. 



The land and fresh-water shells of Scandinavia are 56, all commoii 

 European species ; H. pomai'm- has been naturalized at Stockholm,* 



Dr. Middendorff gives the following list of Siberian shells in his Siiirische 

 Reise (Band II, th. 1. Petersb. 1851) :— 



Helix carthusiana. Irkutsk. Planorbis complanatus, Altai. 



Schrenkii, M. Tunguska,58''. „ albus, Barnaul, „ 



hispida, Beresov. Bernaul. „ contortus, „ 



ruderata, Stanowoj Mtn. „ vortex, „ 



pura, „ „ leucostoma, „ 



sub-personata, „ ; Ochotsk. „ nitidus, Irkutsk. 



Pupa muscorum, Bernaul. Bitliinia tentaculata, Bernaul. 



Zua lubrica, „ „ Kickxii, R. Ami, Altai. 



Succinea putris, „ ; Irkutsk. Valvata cristata, var. Sibirica, Bernard, 



Limnaea Gebleri, :M. Bemaul. Beresov ; Kamtschaika. 



„ auricularia, Nertschinsk. „ piscinalis, R. Ami. 



,. ovata, Bemaul. Unio complanatus, Kamtschatka. 



„ Kamtschatica, Mid. Unio Dahusicus, Mid. Schilka. 



,, peregra, Bernaul, Bei-esov. „ Mongolicus, M. Gorbitra, Dauria. 



„ stagnalis, „ Irkutsk. Aaodon herculeus, M. Scharanai. 



„ palustris, „ „ „ anatinus, Tunguska. 



„ truncatula, „ Tomsk. „ cellensis var. Beringiana, Kamt- 



„ leucostoma, Irkutsk. schatka. 



Pbysa hypnorum, Bernaul; Taimyr- Cyclas calyculata, Bernaul, R. Lena, R. 



lande. Ami, S. Kamts. 



Planorbis corneus, Bernaul; Beresov; Pisidium fontinale, Beresov. 

 Kirgisensteppe, Altai. „ obliquum, Bernaul, Tomsk. 



* Nopske Land- og Fersk-vands Mollusker, Joacliim Friek, 1851, 



