Much of this vvork has of necessity been done in the Botanical Department of the British 

 Museum, and the results are published with the permission of the Trustees. Representative 

 portions of the material studied, photographs of borrowed types, and hundreds of camera-lucida 

 and other drawings are placed for reference in the British Museum Herbarium. 



Thanks to the kindness of Madame Dr. Weber van Bosse, Mons. Bornet, Prof. Lignier, 

 Mons. Lortet, Mons. Hariot, Prof. Nordstedt and Major Reinbold we have been enabled to 

 study the types of many of the species and to draw up fuller descriptions of them than have 

 hitherto been published ; while by other botanists - Dr. F. Börgesen, Mr. F. S. Collins, 

 Dr. M. A. Howe and Prof. R. J. Harvey Gibson — we have been kindly permitted to examine 

 collections, the comparison and study of which have enabled us to gain a wider knowledge 

 oi the variations exhibited by the respective species and a clearer conception of the mutual 

 affinities of the genera. 



Finally we would record our grateful appreciation of Professor and Madame Weber's 

 kindness in inviting us to work out this iftteresting group of algae, and also in allowing us all 

 the time which, owing to prolonged interruptions, became necessary for the completion of the 

 work. To the officials of the Royal Gardens, Kew, we are greatly indebted for the readiness 

 with which they have placed facilities for work at our disposal ; and to Mr. W. R. Wilson 

 of the Department of Printed Books at the British Museum for valuable help given in verifying 

 references in sundry rare volumes unobtainable elsewhere. 



SIKOGA-EXPEDIT1E LXII. 



