to the limit of trees or even considerably beyond it, in the Arctic regions; but they are comparatively very scarce in all cold countries. The Antilles, the Philippine Islands, Equatorial America, and the Mediterranean sub-region are especially rich in this family. Comparatively few of the genera, and those generally small ones, are restricted to single regions; but on the other hand very few are generally distributed, only two-Helix and Pupa-occurring in all the six regions, while Helix alone is truly cosmopolitan, occurring in every sub-region, in every country, and perhaps in every island on the globe.

The Neotropical region is, on the whole, the richest in this family, the continental Equatorial districts producing an abundance of large and handsome species, while the Antilles are pre-eminent for the number of their peculiar forms. This region possesses 22 of the genera, and 6 of them are peculiar.

The Palearctic region seems to come next in productiveness, but this may be partly owing to its having been so thoroughly explored. It possesses 16 of the genera, and 3 of them are confined to it. The great mass of the species are found in the warm and fertile countries surrounding the Mediterranean Sea.

The Ethiopian region has 13 genera, only one of which is peculiar.

The Australian region has 14 genera, 2 of which are confined to the Pacific Islands.

The Oriental has 15 genera and the Nearctic 12, but in neither case are there any peculiar generic types.

The following is the distribution of the several genera taken in the order of their magnitude:

Helix (1,115 sp.), cosmopolitan. This genus is divided into 88 sub-genera, a number of which have a limited distribution. An immense quantity of species have been recently described, so that the number now exceeds 2,000.

Nanina (290 sp.) is characteristic of the Oriental and Australian regions, over the whole of which it extends, just entering the Palearctic region as far as North China and Japan. Isolated from this area is a small group of 4 species occurring

in West Africa. The number of species in this genus have now been increased to about 400.

Clausilia (272 sp.) is most abundant in Europe, with a few species widely scattered in India, Malaya, China, Japan, Equatorial America, and one in Porto Rico. The described species have been increased to nearly 500.

Bulimulus (210 sp.) is American, and almost exclusively Neotropical, ranging from Montevideo and Chili, to the West Indian Islands, California and Texas; with two sub-genera confined to the Galapagos Islands. About 100 new species have been described since the issue of the second edition of Dr. Woodward's Manual

Pupa (210 sp.) abounds most in Europe and the Arctic regions, but has a very wide range, being scattered throughout Africa, continental India, Australia, the Pacific Islands, North America to Greenland, and the Antilles; but it is absent from South America, the Himalayan and Malayan sub-regions, China and Japan. An extinct species has occurred abundantly in the carboniferous strata of North America. About 160 additional species have been described.

Bulimus (172 sp.) abounds most in Tropical South America; it is also found from Burmah eastward through Malaya to the Solomon and Fiji Islands; there are also scattered species in Patagonia, St. Vincents, Texas, St. Helena, and New Zealand. More than 100 additional species have been described.

Buliminus (132 sp.) ranges from Central and South Europe over the whole Ethiopian and Oriental regions to North China, and through the Australian to New Zealand; there is also a single outlying species in the Galapagos Islands. About 50 more species have been described.

Cochlostyla (127 sp.) is almost peculiar to the Philippine Islands, beyond which, are a species in Borneo, one in Java, and two in Australia. Very few new species have been added to this genus.

Achatinella (95 sp.) is absolutely confined to the Sandwich Island group. Recent researches have more than tripled the number of described species.

Achatina (87 sp.) is most abundant and finest in the Ethiopian region, over the whole of which it ranges; but there are also species in Florida, the Antilles, the Sandwich Islands, Ceylon and India. The described species are now more than doubled.

Hyalina (84 sp.) inhabits all Tropical America and the Antilles, North America to Greenland, and Europe to the Arctic regions. Comparatively few new species have been described.

Cylindrella (83 sp.) inhabits the West Indian islands and Guatemala to Texas, with a sub-genus in the Philippine Islands. Species since described have more than trebled the number in this genus.

Cionella (67 sp.) is widely scattered; in India from Ceylon to the Khasia Mountains, Brazil, New Granada, the West Indian islands, Palæarctic, and northern part of Nearctic regions, Pacific Islands, New Zealand, and Juan Fernandez. About 20 new species have since been described.

Glandina (66 sp.), Peru to South Carolina and the Antilles, with three species in Central Africa and one in South Europe. About 40 species have been added to this genus.

Stenogyra (49 sp.), widely distributed: Tropical America and West Indies to Florida, South and West Africa, the Mediterranean region, India and the Philippines. About a dozen new species have been described.

Succinea (41 sp.), widely scattered in all the regions, and in St. Helena, Juan Fernandez, Tahiti, Chiloe, Greenland, West Africa, Himalayas and Australia. The described species are now more than 100.

Partula (39 sp.), Solomon Islands to Tahiti and Sandwich Islands. This genus has also been increased to near 100 species.

Streptaris (34 sp.), most abundant in Tropical South America, but occurs in West Africa, the Seychelles and Rodriguez Islands, Ceylon and Burmah. It now contains over 100 described species.

Spiraris (33 sp.), Yucatan to Mexico, and less abundant in the West Indian Islands. About 20 species have been added.

Macroceramus (27 sp.), Antilles, Florida, and Peru. The species have been more than doubled.

Vitrina (26 sp.), widely scattered through North and Central Europe, North-west America and Greenland, Abyssinia, Madagascar and South Africa, Himalayas to Burmah and Australia. Species since described have more than doubled the number in this genus.

Orthalicus (23 sp.), Bolivia to Mexico and Antilles. This genus has been increased to about 40 species.

Sagda (19 sp.), Antilles only. Very few new species, if any, have been described.

Zonites (12 sp.), South Europe, with one species of a distinct type in Guatemala. The number of species in this genus has

been since about tripled.

Leucochroa (11 sp.), Mediterranean region to Syria and Arabia Petrea.

Simpulopsis (7 sp.), Bahia, Antilles, and far away in the Solomon Islands. Two or three have been added.

Balea (6 sp.), Middle and North Europe, Brazil, and the Island of Tristan d'Acunha.

Daudebardia (6 sp.), Central and South Europe; and a species has since been discovered in New Zealand,

Macrocycles (4 sp.), Chili, California, Oregon and Central North America.

Columna (3 sp.), West Africa, Princes Islands and Madagascar. Stenopus (2 sp.), Island of St. Vincent (West Indies.) Pfeifferia (2 sp.), Philippines and Moluccas.

Testacella (2 sp.), West Europe and Teneriffe. About 8 species have been since described, including one from New Zealand.

Fossil species of Helix, Bulimus, Achatina, Balea, and Clausilia, are found in all the Tertiary formations; while a species of Pupa (as already stated) occurs in the carboniferous formation. For interesting details of the distribution of the subgenera and species of Achatinella in the Sandwich Islands, see a paper by Rev. J. T. Gulick in the Journal of the Linnean Society. (Zoology, vol. xi. p. 496.)

FAMILY 23.-LIMACIDE.-(12 Genera, 116 Species.)

The Limacidæ, or Slugs, are widely distributed, but they are absent from South America, where they are represented by the next family. They also seem to be absent from the greater part of Africa. The genera are distributed as follows:—

Limax (51 sp.), Palæarctic region, Australia and the Sandwich Islands; Anudenus (2 sp.), Himalayas; Philomychus (9 sp.), North America, China and Java; Arion (25 sp.), Norway to Spain and South Africa; Parmacella (7 sp.), South Europe, Canary Islands and North India; Janella (1 sp.), New Zealand; Aneitea (1 sp.), New Hebrides and New Caledonia; Parmarion (4 sp.), India; Triboniophorus (3 sp.), Australia; Testacella (3 sp.), South Europe, Canary Islands, and New Zealand; Hyalimax (2 sp.), Bourbon and Mauritius; Krynickia (8 sp.), Eastern Europe and North America. A few species of Limax, Arion, and Testacella have been found fossil in Tertiary deposits.

FAMILY 24-ONCIDIADE. (2 Genera, 36 Species.)

The Oncidiadæ, or Slugs with a coriaceous mantle, inhabit the Oriental region, Mauritius, Australia, the Pacific Islands, South America and South Europe. The genera are :—