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Show 40-t ISLAND L 1FE. (PAR'L' 1[, · h · h s that they true lungs, and this peculiar metamorp os1s. s ow .. belong to the amphibia rather than to the reptiles. The CreCI~lHS are widely but very sparingly distributed through all the tropiCal regions; a fact which may, as we have seen, be taken a~ a_n indication of the great antiquity of the group, and that rt IS now verging towards extinction. In the ~eychelles ~s:ands two species have been found, named respectively Ocec~l~a oxyttra and a. rost1·ata. The former also inhabits the Malabar coast of India, while the latter has been found in West Africa and also South America. 1 This is certainly one of the most remarkable cases of the wide and discontinuous distribution of a species known· and when we consider the habits of life of these animals and th~ extreme slowness with which it is likely they ?an migrate into new areas, we can hardly arrive at any oth~r conclusion than that this species once had an almost world-w1de range, and that in the process of dying out it has been left stranded, as it were, in these three remote portions of the globe. The extreme stability and long persistence· of specific form which this implies is extraordinary, but not unprecedented, among the lower vertebrates. The crocodiles of the Eocene period differ but slightly from those of the present day, while a small fresh-water turtle from the Miocene deposits of the Siwalik Hills is absolutely identical with a still living Indian species, Emys tect1ts. The mud-fish of Australia, Oe1·atodus joTsteri is a very ancient type, and may well have remained specifically unchanged since early Tertiary times. It is not, therefore, incredible that the Seychelles Crecilia may be the oldest land vertebrate now living on the globe; dating back to the early part of the Tertiary period, when the warm climate of the northern hemisphere in high latitudes and the union of the Asiatic and American continents allowed of the migration of such types over the whole northern hemisphere, from which they subsequently passed into the southern hemisphere, maintaining themselves only in certain 1 Specimens are recorded from West Africa in the P1·oceedings of the Academy of Natural Science, Philadelphia, 1857, p. 72, while specimens in ·the Paris Museum were brought by D'Orbigny from S. America. Dr. Wright's specimens from the Seychelles have, as he informs me, been determined to be the same species by Dr. Peters of Berlin. CIIAl'. XIX.] TllR MADAGASCAR GHOUP. 405 limited areas where the physical conditions were especially favourable, or where they were saved from the attacks of enemies or the competition of higher forms. Fresh-water Fishes.-The only other vertebrates in the SeyC~ lelles are two fresh-water fishes abounding in the streams and nvulets. One, Haplochilus playfairii is peculiar to the islands but there are al~ied species in Madagascar. It is a pretty littl~ fish about four mches long, of an olive colour, with rows of red s~ots, and is ver~ abundant in some of the mountain streams. 'l he ~shes .of this genus, as I am informed by Dr. Gunther, often mhab1t both sea and fresh water, so that their migration from Madagascar to the Seychelles and subsequent modification, offers no difficulty. The other species is Fundulus orthonot~ts, found also on ~he east coast of Africa; and as both belong to th.e same. fami!Y ~ Cyprinodontidre-this may possibly have migrated m a s1m1lar manner. Land-shells. - The only other group of animals inhabiting the Seychelles which we know with any approach to completeness,. are the land and fresh-water mollusca, but they do not ~urmsh any facts of special interest. About forty species are known, and Mr. Geoffrey Nevill, who has studied them thinks their meagre number is chiefly owing to the destructi~n of so much of the forests which once covered the islands. Seven of the species-and among them one of the most conspicuo\1s, Achatina fulica-have almost certainly been introduced; and the remainder show a mixture of Madagascar and Indian forms, with a preponderan~~ of the ~~~ter. Five genera-Streptaxis, Cyathoponea, Onch1dmm, Hehcma and Paludomus, are mentioned as bein(" especially Indian, while only two-Tropidophora and Gibbu; are found in Madagascar but not in India.1 About two-third~ of the species appear to be peculiar to the islands. Matwitius, Botwbon and Rodriguez. -These three islands are somewhat out of place in this chapter, because they really belong to the oceanic group, being of volcanic formation, surrounded by deep sea, and possessing no indigenous mammals or amphibia. Yet their productions are so closely related to those of Madagascar, to which they may be considered as attendant , 1 "Addi.lio~al Notes on tl1o Land-shells of tlte Seychelles Islauds. '' By Geoffrey Nevill, C. M.Z.S. Fl'oc. Zool. Soc. 186~, p. Gl. |