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THE HABITAT OF CERTAIN SPECIES OF CLAUSILIA FROM 

 DALMATIA, HERZEGOVINA, AND BOSNIA. 



By Eev. A. H. Cooke, M.A., F.Z.S. 



Bead I2th June, 1908. 



A KECENT excursion into Dalmatia, Herzegovina, and Bosnia gave me 

 an opportunity of making some observations upon certain of the Land 

 Mollusca. The results of these observations may prove interesting to 

 those who study, not the shell, nor the ' animal,' but the habits and 

 modes of life of the creature as a whole. 



The first point that struck me was this. Although April was well 

 advanced (I was in the country from the 11th till the 28th), and 

 the warmth considerable, summer clothes being a necessity even at 

 Sarajevo, 1,800 feet above the sea, the Mollusca were still hibernating, 

 with certain remarkable exceptions. Clausilia, Pupa, and Pomatias 

 were lively and abundant; of the Helicidse, the only species that 

 could be said to be ' out ' was austriaca, Miihl., but Velebitana, Zieg., 

 and setosa, Zieg., appeared to be just awakening, while others had to 

 be hunted out in their lairs. The great Zonites (acies, L., compressus, 

 Zieg.) and Glandina {Algira, L.) were still in winter retirement, 

 some way below the surface of the ground. It looked as though the 

 smaller- sized genera were better equipped for resisting cold than the 

 larger, or perhaps their more elongated form makes it impossible for 

 them to feed up for the winter, and to get into such good condition as 

 their larger brethren. 



It was therefore to Clausilia that my attention was more particularly 

 directed. One cardinal fact soon impressed itseK with regard to this 

 genus. Variety of habitat was its prime characteristic. The first 

 species which occurred was at Pola, where a form of the common 

 CI. papillaris, L., was nestling in twos and threes in shaded cracks of 

 dry walls and rocks. In the mountains behind Spalato, at a height 

 of about 1,200 feet, CI. fulcrata, Zieg., was found in quantity under 

 similar conditions. But at 1,000 feet lower level, where the Elver 

 Jadro issues fully - grown from the face of the limestone cliff, 

 CI. archilahris, Kiist., was found plentifully on smooth rocks, never in 

 groups, like the two species just named, but almost invariably one at 

 a time. On the Monte Mariano, about 600 feet above Spalato, 

 CI. semirugata, Zieg,, occurred abundantly under large stones, but not 

 in tbe open, although, rocks abounded all round, while in the 

 same locality CI. Cattaroensis, Kiist., was found on the rocks, but 

 never under stones. 



A further contrast was noticeable at the lovely defile of Almissa, to 

 which I made a special expedition in order to obtain the magnificent 

 species — surely the largest Clausilia in Europe — which takes its name 

 from the spot. So fine a shell is it, that I could hardly believe my good 

 fortune when my eyes lighted upon the first individual. But it was 

 no use looking for it in cracks, or in old walls, or under stones, or in 

 any of the haunts usually dear to Clausilia. It occurred on the bare 



