Litoral diatoms from the Malay Archipelago. 



In exaraining the numerous samples collected by Dr. C. Aurivillius in the Malay 

 Archipelago, I noted a nuinber of litoral diatoins, which increased considerably when 

 I examined a sample of shell-sand brought home from Java by the same scientist. 



There are already two catalogues of the diatoms of the Malay Archipelago, viz. by 

 Dr. Leuduger-Fortmorel (Diatomées de la Malaisie, Annales du Jai-d. Bot. de Bniten- 

 zorg Vol. XI 1892) and by E. de Wildeman (Prodrome de la flore algologique des Indes 

 Néerlandaises Batavia 1897). The former is the result obtained by examiiiing samples 

 collected by J. Deby, supplemented b}' notes from the litex"ature, and contains a 

 very large number of registered forms. The latter does not seem to be the i-esult of 

 any original researches. In looking över the lists of Dr. Leuduger-FortmoreI one is 

 surprised to find atnong the diatoms of the Malay Archipelago such species as Campylo- 

 cliscus anfiularis, Grammatophora idandica, Rhahdonema nrcuntiim, E. minutwin, Biddulphia 

 haltvna etc. Either the determinntions may be erroneous or the samples and slides have 

 been contaminated by materials of foreign origin. The same is the case with many ca- 

 talogues of diatoms, so that the present literature is crowded with erroneous notes about 

 the geographical distribution. Thus many forms have been set down at »cosmopolitan». 

 According to ray experience most diatoms have a limited distribution, and they seem to 

 me to be in several respects very suitable for the study of the geographical distribu- 

 tion of the organisms. Nevertheless, no trustworthy generalisations can be derived from 

 the actual literature in its present unreliable condition. 



As the samples brought home by Dr. Aurivillius are of certain origin, have been 

 cleaned and mounted by myself, no other sources of errors in the foUowing catalogue 

 are possible than in the determinations. Therefore I consider this list to be of a certain 

 importance for the knowledge of the geographical distribution of marine diatoms. 



The frequency has been indicated in the following pages by the signs r?'. very 

 rare, r. rare, -f- not rare, e. common. 



Amphora duhia A. S. Bali Sound v., Java r. 



A. mexicana A. S. Billiton r. 



A. gigantea, Grun. Java r., Billiton r. 



A. oculus A. S. Java rr. 



A. crassa Greg. Java -|-, Bali Sound r. 



K. Sv. Vet. Akad. Hand]. Band 35. l^:o 5. 4 



