364 MESSES. E. HEEON-ALLEN AND A. EAELAND ON THE 



Unfortunately, our information regarding the geography and geology of the adjacent 

 African coast is scanty in the extreme, but we are informed by Dr. Simpson that it 

 consists mainly of (1) extensive sandy beaches, (2) stretches of rock-bound coast, and 

 (3) mangrove swamps, which, as usual, mark large muddy areas. The thirty-seven 

 main islands of the Archipelago are, for the most part, of coral formation, and are 

 surrounded by both fringing and barrier reefs, and the great majority lie low upon the 

 sea-level and are densely wooded. The highest altitude is attained on Wamizi Island 

 (S3 ft.), many are hardly more than rocks not more than 6-10 ft. out of water at high 

 tide, whilst a vast number of the reefs are only uncovered at low water. The 100- 

 fathom line, which follows the coast-line to some extent, lies at distances varying from 

 two to twenty miles from the mainland, so that the whole district may be regarded as 

 a semi-submerged plateau. " The most marked feature in the formation of the coast," 

 says Dr. Simpson, " is the division into large ' passes,' and the regularity with which 

 the islands and reefs form extensions to the Capes of the mainland. These deep 

 indentations in the 100-fathom line between the various reefs and islands, through 

 which the current flows to the inner bays, are known as ' passes.' " 



In examining the sixteen samples of material which have come into our hands, Ave 

 have been privileged to deal with what is virtually an untouched area. H.M.S. 

 ' Challenger ' left the Cape of Good Hope at Christmas, 1873, and proceeded due 

 south-east to Prince Edward's Island and the Antarctic Circle, and never approached 

 the east coast of Africa. In 1867 Dr. E. Perceval Wright made several dredgings in 

 the Seychelle Islands. Only one sample from between St. Anne and Long Island was 

 preserved, which was examined by Dr. H. B. Brady, and the results were communicated 

 by Dr. Wright to the Royal Irish Academy in 1876 *. In this communication 

 38 species were noted, none of which was new to science, with the exception perhaps 

 of a Patellina (No. 30) which was neither diagnosed nor named. In 1880 Dr. Karl 

 Mobius published a highly important paper on the Foraminifera of Mauritius f, to 

 which we shall frequently have occasion to refer in the second part of this Monograph. 

 Mobius recorded forty species, seven of which were described as new, and his Monograph 

 is illustrated by fourteen superb plates, dealing largely with the biological features of 

 the group. In the j'ear 1893, Dr. J. G. Egger published his important work on the 

 Foraminifera collected by S.M.Sch. ' Gazelle '$. The Stations which particularly' 

 concern our area are as follows : — 



* E. Perceval Wright, M.D. " Notes on a small Collection of Foraminifera from the Seychelles," Proo. 

 Koy. Irish Acad. ser. 2, vol. ii. 1876, pp. 586-588. 



t K. Mobius. In K. Mobius, F. Eichter, and E. von Martens, ' Beitriige zur Meeresfauna der Insel 

 Mauritius und der Seycbellen ' (Berlin, 1880), pp. 63-110, " Foraminifera von Mauritius," pis. i.-xiv. 



+ J. G. Egger. " Foraminiferen aus Meeresgrundproben gelothet von 1874 bis 1876 von S.M.Sch. 

 ' Gazelle,'" Abhandl. der k. bayer. Ak. d. "Wiss., CI. ii. Band xviii. Abth. 2 (Munich, 1893), pp. 195-457, 

 pis. i.-sxi. 



