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Show 400 ISLAND LIFE. [rART n. . h d s already stated, they an active volcano 8,500 feet hig ; an ' a h 500 £ th are situated on a submarine bank with less t an . a oms . d 'th Africa There IS reason soundings, connectmg Ma agascar WI · . to believe however that these islands are of comparatively . '. d th t the bank has been formed by matter recent ongm, an a b 1 val Any how there is ejected by the volcanoes or y up 1~a · _ _ no I. n dl'C a t1' 0n wb a t ever of there havmg been he. ro a lan.d con nectw. n b etween M a d aga..s. ca·r and Africa·' wh1le the Islands h l h b mal.nly colonised from Madagascar, to t erose ves ave een the 100-fathom bank surrounding which some of them make a near approach. . Th e 0 omoros cont aI ·n t""r o land mammals, a le.m ur a. nd a civ. et, b oth of M a d agascar genera and the . latter an I.d entical s.p ecies, d th · J 0 an ere IS as a peculiar specieS of fru1t.- bat (Fte. ro.p us · ) O'roup which ranO'eS from Austraha to Asia and. comorens~s , a o o . Madagascar, but is unknown in Africa. Of la~d-buds fo:ty-one spec1· es ar e known , of which sixteen are pecuhar to the. Island.s , twenty-one are found also in Mada~ascar, and tbre~ found. m Africa and not in Madagascar ; w bile of the pecuhar species, six belong to Madagascar or Masca~ene genera. These facts point to the conclusiOn that the .Comoro Islands have been formerly more nearly connected w1th Madagascar than they are now, probably by mea~s of intervening islets and the former extension of the latter Island to the westward, as indicated by the extensive shallow bank at its northern extremity, so as to allow of the easy passag~ of birds, and the occasional transmission of small mammaha by means of floating trees.I . . . . The Seychelles Archipelago.-This mterestmg group cons1sts of about thirty small islands situated 700 miles N.~.E .. of Madagascar, or almost exactly in the line formed by contmumg the central ridge of that great island. The Seychelles st~nd upon a rather extensive shallow bank, the ~00-fathom hne around them enclosing an area nearly 200 miles long ~y 100 miles wide, while the 500-fathom line shows an exten~10n of nearly 100 miles in a southern direction. All the larger Islands 1 For the birds of the Comoro Islands see Proc. Zool. Soc., 1877, P· 295, and 1879, p. 673. CHAP. XlX. J THE .MADAGASCAn GROUP. 401 are of granite, with mountains rising to 3,000 feet in Mahe, and. to from 1,000 to 2,000 feet in several of the other islands. We c.an therefore hardly d?ubt that they form a portion of the great hne of upheaval wh1eh produced the central granitic mass of Madagascar, · intervening points being indicated. by the Amirantcs, the Providence, and the Farquhar Islands, which, though all coralline, probably rest on a granitic basis. Deep ~hannels of more than 1,000 fathoms now separate these Islands from each other, and if they were ever sufficiently elevated to be united, it was probably at a very remote epoch. The Seychelles may thus have had ample facilities for r~ceiving from Madagascar such immigrants as can pass over narrow seas; and, on the other hand, they were equally favourably situated as regards the extensive Saya de Malha and Cargados banks, which were probably once large islands, and may have supported a rich insular flora and fauna of mixed Mascarene and Indian type. The exjsting fauna aud flora of the Seychelles must therefore be looked upon as the remnants :Vhich have survived the partial submergence of a very extensive Island; and the entire absence of mammalia may be due, either to this island having never been actually united to Madacrascar 0 ' or to its having since undergone so much submergence as to have led to the extinction of such mammals as may once have inhabited it. The birds and reptiles, however, though few in number, are very interesting, and throw some further light 011 the past history of the Seychelles. Birds of the Seychelles.-Fifteen indigenous land-birds are known to inhabit the group, thirteen of which are peculiar species, 1 belonging to genera which occur a] so in Madagascar or 1 The following is a list of these peculiar birds. (See the Ibis, for 1867, p. 359 ; and 1879, p. 97.) PASSERES. Ellisia seychellensis. Copsychus seychellarum. Il ypsipetes crassi1·ost1'is. Tchitrea corvina. Nectm·inia dussumieri. Zosterops modesta. , semiflava. Foudia seychellarum. PSITTACI. Coracop.<Jis bm·klyi. Palmornis wardi. Cor,uMBlE. A lecim·cenas pulche1·rimus. 'l'urtur rost1·atus. ACCIP!Tll.ES. Tinnunculus gracilis. D D |