originally placed. I have also a few specimens of a minute Madeira species, Helix lentiginosa, Lowe, which I have ascertained to be alive, although they are so small that it is difficult to conceive how sufficient moisture to support life can have been retained through this long period."

1

Three specimens of Helix bicarinata (Porto Santo), recently obtained from an English dealer and kept by Mr. Gude in a glass-topped box for fifteen or sixteen months, on being tested in water, proved to be alive and crawled freely about among damp moss.

BULIMUS PALLIDIOR is said to have survived confinement in a box, without food, during a period exceeding two years and two months: a living individual exhibited by Dr. Stearns at a meeting of the California Academy of Sciences in 1875 was stated to be one of nine which had been collected in Lower California in March, 1873, kept in a box undisturbed till June, 1875, and then revived in a jar containing some vegetable food and a small quantity of tepid water; subsequently, however, all had died, except the one exhibited, which, though not very active, seemed in pretty good health.2

1

J. S. Gaskoin," Proc. Zool. Soc.," 1850, pp. 243-4: Woodward and Wollaston, "Ann. and Mag. Nat. Hist.," (2), vi. (1850), pp. 489-90; and see also Woodward's "Manual," ed 4, rep. 1890, p. 14.

2 R. E. C. Stearns, "Am. Nat.,” xi. (1877), 100; and "Proc. California Academy of Sciences," October 18th, 1875, as quoted in 'Ann. and Mag. Nat. Hist.," (4), xix., pp. 355-6 and “Quart. Journ. Conch.," i., p. 218.

66

BULIMUS ROSACEUS.-Four individuals of a large Bulimus from Valparaiso, as related by Sir C. Lyell in the "Principles," were brought to England by Lieutenant Graves, who accompanied Captain King in his expedition to the Straits of Magellan; they had been "packed up in a box, and enveloped in cotton, two for a space of thirteen, one for seventeen, and a fourth for upwards of twenty months," but, when exposed by Mr. Broderip to the warmth of a fire in London, and provided with tepid water, Lyell saw them revive and feed greedily on lettuce-leaves. B. rosaceus seems to be the species referred to, of which Captain King, in a paper on the Mollusca, etc., collected by the "officers of H.M.S. Adventure and Beagle employed between the years 1826 and 1830 in surveying the southern coasts of South America including the Straits of Magalhaens and the coast of Tierra del Fuego," gives the following

note:

"Soon after the return of the expedition, my friend, Mr. Broderip, to whose inspection Lieutenant Graves had submitted his collection, observing symptoms of life in some of the shells of this species, took means for reviving the inhabitants from their dormant state, and succeeded. After they had protruded their bodies, they were placed upon some green leaves, which they fastened upon and ate greedily. These animals had been in this state for seventeen or eighteen months, and five months subsequently another was found alive in my collection, so that this last had been nearly two years dormant. These shells were all sent to Mr. Loddige's nursery,

where they lived for eight months, when they . . all died within a few days of each other."1

BULIMUS EREMITA.-A specimen of this snail, from Turkestan, said to have been kept dry for two and a half years, revived and ate, but died after three or four days."

PUPA TRIDENS AND CLAUSILIA RUGOSA.-Some snails, apparently belonging to these species, collected in France and close-packed in a pill-box by Mr. John Curtis in July, 1830, and subsequently kept in a dry place without food for nine months, on being placed on wet moss were seen to revive within twenty-four hours.3

4

OPERCULATE SNAILS.-The Cyclostomas, according to a statement in Woodward's "Manual," are well known to be able to survive imprisonments of many months. Some foreign species, procured by Mr. Pickering from a dealer, and kept by him for some weeks, are said to have revived in water. Numerous examples of C. articulatum, collected in February, 1858, by Madame Ida Pfeiffer, in the Island of Rodriguez, and conveyed from thence to Mauritius, continued active, without taking food, during a stay there of two

1 Lyell, "Principles,” ii. (1875), p. 377; P. P. King, “Zoological Journal," v. (1835), p. 342.

2 Goldfuss, as quoted in the "Zoological Record,” xxi. (1884), Moll., p. 19.

3 J. Curtis, "Trans. Lin. Soc.," xvi. (1833), 766-7.

4 Ed. 4, rep. 1890, p. 14.

5 S. P. Woodward, “Ann, and Mag, Nat, Hist.,” (2), vi. (1850), 489-90.

I

months, and three individuals remained alive after the voyage to England, which occupied ten weeks. They were brought over, packed in paper and rags, in a tin box with a lid, and were not taken out until a fortnight after their arrival. One lived for some months under a bell-glass with moss and ferns.' A specimen of Rhaphaulus chrysalis, collected in the month of January by Captain R. H. Sankey, remained closed in its shell until 27th of June, when it yielded slowly to the means employed to revive it, finally moving about and creeping freely under an inverted glass. Cyclophorus indicus, from Bombay, was once received by Mr. Benson in a living state, after a voyage round the Cape, occupying four months. According to a statement by Mr. John Curtis in 1831, operculate molluscs have been reanimated after having remained dormant in cabinets for very long periods, "it has been said for forty years"! 3

2

3

1 S. P. Woodward, "Ann. and Mag. Nat. Hist.," (3), iv. (1859), 320.

2 W. H. Benson (on R. chrysalis and C. indicus), “Ann. and Mag. Nat. Hist.,” (3), iv. (1859), 93-4.

3 J. Curtis, "Trans. Lin. Soc.," xvi. (1833), 766-7.

CHAPTER VI.

MEANS OF DISPERSAL.

A CLUE to the almost universal distribution of many families and genera of land-shells is to be found, Mr. Wallace observes, in their immense antiquity: in the Pliocene and Miocene formations, he says, most of the remains of these creatures are either identical with or closely allied to living species, while even in the Eocene almost all are of living genera; no true landshells have been found in the Secondary formations, but they must certainly have abounded, for in the far more ancient Palæozoic coal measures of Nova Scotia two species of the living genera Pupa and Zonites have been discovered in considerable abundance. Types having thus "survived all the revolutions the earth has undergone since Paleozoic times," are hardly likely to be confined by now existing arms of the sea, mountain chains, and other similar barriers which have effectually limited the ranges of many groups of higher animals.' But it is obvious, of course, that antiquity in itself, however great, could have effected nothing without migra

1 "Geographical Distribution," ii. p. 528; “Island Life," pp. 76-7, ed. 2, p. 79.