COOKE : ox THE GENUS CLAVSILIA. 253 



British Isles. — In Britain we have five species of Clausilia, 

 belonging to the four sub-genera Marpessa (latninata, Mont.), Alinda 

 {biplicata, Mont.), Cusmicia (^dubia, Drap., bidentata, Str.), Pirostoma 

 {rolphii, Gray). The present distribution' of these species in 

 Britain is — 



laminata : All England except Cornwall and Hunts, but only in 

 three of the twelve counties of Wales, viz. Glamorgan, Merioneth, 

 Denbigh ; Edinburgh, Fife and Kinross, Mid and North Perth, 

 Kincardine; Ireland in six counties only, stretching north-west and 

 south-east from Sligo to Wicklow. 



biplicata: Surrey, Middlesex, Herts, Cambs (all adjacent counties), 

 Gloucester East. Hapidly becoming extinct. 



diibia : I omit, tlie range being still under question. 



bidentata : All British islands from Jersey to Shetland. 



rolphii : All south and south-east counties south of Thames (except 

 Dorset, Somerset, Cornwall), Herts, Northants, Monmouth, Salop, 

 Lincoln (furthest north). Not in Ireland. 



The following species, now living on the Continent, have been 

 found fossil only in England : parvula, Stud. (Pliocene, Hunts) ^ ; 

 pumila, Zgl., var. sejimcta, West. (Pleistocene, Cambs, Hunts) ; 

 ventricosa, Drap. (Pleistocene, Hunts) ; plicatula, Drap., from 

 Copford (S. V. Wood, Crag Mollusca, ii, p. 307), is a misidentification 

 for rolphii. The following have not been identified with any 

 Continental forms : striatula, Edw. (Eocene, Isle of ^\^i), plioce^ia, 

 S.V.Wood (Coralline Crag, Suffolk). 



Scandifiavia mid Detimar/c. — Norway and Sweden, from their close 

 connexion with the Continent, are far richer in Clausilia than Britain. 

 All our five species occur in one or the other, and Norway possesses 

 three and Sweden four besides. No sub-genus is present which is not 

 also British. The occurrence of a Papillifera {nilssoni, West.) in 

 Sweden seems very doubtful, C. rolphii reaches Christiania,^ biplicata 

 and 2^^i('(^tula, Bergen, laminata has been found at Trondhjem, and 

 bidentata as far north as Tromso (69° 40' N.) ; cruciata, Stud., which 

 reaches Sweden, has not yet been found in Denmark. 



Denmark, on the whole, is not a very favourable country for 

 Clausilia. Ten species are found, and all the sub-genera are still 

 those of North Europe. Three species occur which are not in Norway 

 and Sweden, viz. parvtila, Stud. (Zealand, very rare), pumila, Zgl. 

 (Zealand and Bornholm, doubtful from Scandinavia), lineolata, Held 

 (South and East Fiinen only). Schleswig-Holstein shows no 

 addition to the list. There is no Clausilia in the North Frisian 



^ The facts are taken in the main from the official records of the Conchological 

 Society, and are kindly furnished me by Mr. W. D. Eoebuck. For 

 bidentata in Shetland, see Jeffreys, Brit. Conch., i, p. 279. 

 ^ I am indebted to the kindness of Mr. A. S. Kennard for this information. 

 ^ The following seems interesting : — 



Furthest north in England. In Norway. 



rolphii . . .53° 30' N. lat. . . 60° N. lat. 

 biplicata . . . 52° 30' ,, . . 61° ,, 



laminata . . .57° ,, . . 64° ,, 



