92 PUOCKKDINGS OF THK MALACOLOGICAL SOCIETY. 



well-marked riblets, occurs in fair abundance. When you get to the 

 top of the Krepatura, you step over a little saddle, perliaps 40 feet 

 Avide, and descend equally steeply on the other side. The moment 

 you get to the top, A. Fussiana, var. insignis, stops dead, and is 

 replaced on the rocks of tlie Schlucht on the other side by a dextral 

 form, A. Fussiana, var. 2)>'w'>wsa, Parr. 



A. Biehi, Pfr., vai'. Potaissanensis, Kim., occurs only in the 

 Schlucht of Torda, and I made a special expedition to Torda to obtain 

 it. The Schlucht, Avhose perpendicular limestone sides appeared most 

 favourable for tlie occurrence of Alopia, was searched from one end 

 to the other without the slightest success. At last, when almost 

 giving up the search in despair, one came upon it in abundance on 

 a certain buttress of steep rock, but, search as one might on both sides 

 of the Schlucht, not a single specimen was found except on this patch 

 of rock, which measured no more than 30 feet in length, and 

 appaientlj' differed in no respect fi'om neighbouring patches. 



Put the Donghavas mountain is perliaps more remarkable than any 

 for its breeding of varieties. It is a round, stumpy mountain of about 

 5.000 feet, covered with forest, and with streaks of limestone cliff on 

 all its faces. Kimakowicz enumerates five distinct varieties of Alopia 

 from different sides of the mountain, and all peculiar. I cannot 

 pretend to have found all these, but I found three forms of the same 

 species wholly distinct from one another, each occurring within 

 sharply defined limits. IS^ot half a mile from the Donghavas rises 

 another mountain, the Tesla, also round-topped, covered with forest, 

 and with streaks of limestone cliff. On the Tesla cliffs an Alopia 

 {(/laiica, Bielz) occurs, entirely distinct from anything in the 

 Donghavas, and scarcely varying at all, while A. Haueri on the 

 Donghavas has five separate varieties. 



Alopia elegans, Bielz, a very well-marked species, is confined to 

 the Dumboviciora Schlucht in lloumania, on the far south side of the 

 Kuuigstein. Two good varieties are found in the upper part of the 

 same Schlucht, cerasina, A. Schm., and intercedejis, A. Schm. 



Although the species and varieties are so numerous, and although 

 the area over which the majority of the gi'oup occurs is relatively so 

 small, the species never overlap. No two distinct species ever live 

 togetlier on the same cliff face. So far as external features go, the 

 Malajester, Propasta, Bogater, Dumboviciora Schluchten appear 

 equally adapted for the habitation of Alopia, and yet each has its one 

 species and no more, the Malajester livida, Menke, the Dumboviciora 

 elegans, Bielz, the Bogater Bogatensis, Bielz, the Propasta Lischheana, 

 Parr., the Krepatura Fussiana, Bielz, var. insignis. In the two latter 

 cases, the Schluchten in question form part of the same mountain, which 

 is not of great area, and open on to the plain at no great distance 

 from one another. 



These restrictions of locality perhaps do not stand alone and could 

 be paralleled by similar instances in other genera. But what makes 

 them more remarkable in this case is, that many other forms of 

 Clausilia, not being Alopia, occur abundantly all over the district, 

 with no such restrictions of distribution, and no appreciable tendency 



