COOKE: ON THE GENUS CLAUSILIA, 255 



almost entirely northern ; the greater altitude balancing the more 

 southern latitude. One observes little that is characteristic in the 

 lists that are published. Marpessa orthosfoma, Zgl., penetrates to 

 the cantons of Neuchatel, Berne, and Vaud, and is even found in 

 the neighbourhood of Basel. One Alpine species, Dilataria diodon. 

 Stud., appears to be peculiar to Canton Wallis. The fauna of the 

 Swiss valleys to the south of the Alps naturally has a North Italian 

 character; Delitna, for instance, penetrates to the southern base of the 

 mountains, and at Lugano D. itala, Mts., is abundant. 



Austria- Hungary . — Clessin's work (18) excludes Bosnia, Herze- 

 govina, and Dalmatia, and the group Alopia will be treated of 

 separately. Even with these subtractions the lists include sixty 

 species (and more have since been added), classified as follows : — 



Widely distributed species . . . 11 



Eastern species ..... 22 



Southern species . . . . . 15 



Alpine species . . . . . . 12 



The principal features of this rich fauna are («) the great increase 

 of Ifarpessa, 13 spp., six of these being ' southern ' and five 'eastern,' 

 forms; {b) the increase of Cusmicia (9 spp.), Pirostoma (9 spp.), and 

 Graciliaria (5 spp.); (<•) the appearance of a couple of Herilla and 

 Idyla, thoroughly East European groups ; {d) the occurrence of 

 Pseudalinda (4 spp.) and Uncinaria (8 spp.) in Transylvania, and of 

 Delima (4 spp.) in South Tirol and other southern states. The lime- 

 stone regions of Styria, Carinthia, Croatia, with the Banat in South 

 Hungary, and the Siebenbiirgen region in the Far East, are all rich 

 districts, abounding in species. The Velebit range, separating South 

 Croatia from North Dalmatia, is anotlier thickly populated region, 

 from which many new, and some dubious, species are described. 



The occurrence of about seventy-two species, sub-species, and 

 varieties of the sub-genus Alopia, which crowd the cliffs of the East 

 Carpathians, and have outliers as far west as Torna, not far from 

 Buda Pesth, is one of the most striking features of the European 

 Clausilia fauna. Sober considerations may reduce the species to about 

 twenty; at least five of these are destitute of clausilium ; some species 

 are dextral, others sinistral, others indifferently dextral or sinistral. 

 The range of individual species is singularly contracted, often to the 

 limits of a solitary mountain-top, a ravine, a limestone cliff. Authors 

 agree in placing the group in close relationship with the extinct 

 Triptychia (which lacks clausilium) on the one side, and with 

 Hualopia (Lower and Middle Miocene) and Triloba on the other. No 

 one who has ever collected Alopia can fail to be struck with its entire 

 divergence, as regards general habits, from any other Clausilian 

 group. A species has been reported from North Greece, and two 

 others from Montenegro (see p. 256) ; further examination of their 

 true position is desirable. 



Bosnia, Rerzegovina, and Dalmatia are rich in Clausilia beyond any 

 other part of Europe. In North Bosnia we have the huge Herilla 

 bosnica, Pfr., and H. dacica, Eriv., which rank among the largest 



