Fig. 198.—Helix (Iberus) strigata Müll., Florence.
Italy, with the neighbouring islands, has a rich molluscan fauna. In the sub-Alpine districts of northern Italy the prominent Helix groups are Campylaea, Pomatia, and Anchistoma, which in the south are generally replaced by Iberus, which here attains its maximum development. Large Hyalinia are abundant in the north, and Pomatias and Clausilia are frequent all along the Apennines. Sicily has about 250 species, half of which are peculiar. Helices of the Iberus type abound, but Campylaea is reduced to two species. Many peculiar forms of Clausilia occur, especially a latticed type of great beauty. Ferussacia and Pupa are well represented, and there are one each of Glandina and Daudebardia.
Dalmatia and the adjacent districts are chiefly remarkable for the rich development of Clausilia, which here attains its maximum (nearly 100 species). The Campylaea section of Helix is represented by its handsomest forms, many of which are studded with short hairs. Here too is the headquarters of Zonites proper, which stretches westward as far as Provence, and eastward to Asia Minor; and also of the single European Glandina, which has a similar eastward range, but spreads westward through Italy and Sicily to Algeria, not occurring in southern France. The land operculates are chiefly represented by Pomatias, and among the fresh-water operculates are a Melania and a Lithoglyphus, the latter having probably spread from the basin of the Danube.
Fig. 199.—A, Clausilia crassicosta Ben., Sicily; B, Clausilia macarana Zieg., Dalmatia; B´, clausilium of same.
(iv) The Egypto-Syrian district extends along the south-eastern shores of the Mediterranean from Tripoli to North Syria, and eastward to the Euphrates valley. Lower Egypt alone belongs to this portion, the fauna of Upper Egypt being of an entirely tropical character, and belonging to the Ethiopian Region.
Lower Egypt.—The Mollusca of Lower Egypt stand in the unique position of belonging, half to the Palaearctic, and half to the Ethiopian Region. The land Mollusca are of a distinctly Mediterranean type, while the fresh-water, directly connected as they are by the great highway of the Nile with regions much farther south, contain a large admixture of thoroughly tropical genera (Ampullaria, Lanistes, Melania, Cleopatra, Corbicula, Cyrena, Iridina, Spatha, Mutela). The Helices, which are not numerous, are rather a mixture of circum-Mediterranean species than of a specially distinctive character. H. desertorum, however, belonging to the group Eremophila, is characteristic. There is a single Parmacella, but the physical features of the country are unfavourable to the occurrence of such genera as Clausilia, Pupa, Hyalinia, and the land operculates.
Syria.—The Mollusca, especially in the more mountainous regions of the north, are much more varied and numerous than those of Egypt. Clausilia is again fairly plentiful, and the Helicidae are represented by some striking forms of the sections Levantina, Pomatia, and Nummulina. Leucochroa has several curious types with a constricted aperture, and the Agnatha are represented by Libania, a peculiar form of Daudebardia. A prominent feature is the occurrence of a number of large white Buliminus of the Petraeus section (Fig. [200]). Land operculates appear to be absent, but Melanopsis and Neritina are abundant. The Dead Sea contains no Mollusca, but Lake Tiberias has a rich fauna, including the above-mentioned genera, with a Corbicula and several Unio.
