374 welwitsch's African marine alg^e. 



16. Centroceeas Kiitz. in Limiaea, 1841, 741. 



1. C. clavulatum Mont. Loanda: on rocks covered by sand on 

 the shore near Fort de Concei^ao ; Dec. 1853. No. 61. Near 

 S. Pedro ; Feb. and April, 1854. No. 64. On rocks of the sea near 

 Morro das Lagostas and S. Pedro, frequent; Jan. 1854. No. 66. 



Geofjr. Dlstr. Tliroughout all tropical and subtropical seas. 



17. Peyssonelia Dene. PI. Arab. 168. 



1. P. RUBRA J. Ag. Loanda: on rocks and various algae, Praia 

 de Penedo ; Jan. and Feb. 1854. No. 121. Island of Loanda, 

 May, 1854, No. 123. St, Vincent, Cape de Verde : on rocks and 

 various algte near volcanic rocks, but rarely well developed ; 22 Aug, 

 1858. No. 233. Prince's Island : on rocks in the Atlantic, here 

 and there, growing gregariously ; 21 Sept. 1853. No. 256. 



(Jeogr. Distr. Adriatic, West Indies. 



2. P. Harveyana Crn. Loanda : Morro das Lagostas, July, 

 1854. No. 122. St. Vincent, Cape de Verde: Praia de Gale, 

 22 Aug. 1853, No. 236. 



Geogr. Distr. Atlantic shores of Europe. 



18. Grateloupia Ag, Spec. Alg. i, 221. 



1, G, LANCEOLA J, Ag, Loanda : fronds gregarious, chiefly 

 covering the sides of rocks and stones ; fertile plants always much 

 branched, when sterile smaller. Colour when alive a dark steely 

 purple. Hab. on the Angola shores near Morro das Lagostas, rare, 

 on rocks ; July, 1864. No. 120. 



Geogr. Distr. North Atlantic (Africa). 



19. Melobesia Lam, Hist, Polyp, Flex, 313, 

 1, M, corticiformis Kiitz, St. Vincent, Cape de Verde: on the 

 fronds of Gelidium rigidwn, on the shore ; Aug, 1853. No. 251. 

 Geogr. Distr. Atlantic, Mediterranean, Cape of Good Hope, 



20, CoRALLiNA L, Syst, Nat, ed. 12, i, pt. ii. 1304. 



1. C. OFFICINALIS L. Madeira: Praia de Camara dos lobes; 

 Aug. 1853. With No. 268. 



Geogr. Distr. Arctic Sea, North and South Atlantic, Mediter- 

 ranean, Black Sea, Cape of Good Hope, West Indies, North and 

 South Pacific, Australia. 



A certain number of the algae collected by Dr. Welwitsch are 

 not sufficiently well preserved to be named specifically, and are 

 therefore not given here. Among these are species of Cgonophycece, 

 Cladophora, Sargassum, Dictijota, Corallinea;, Gracilaria, Pohjsiphonia, 

 and Nitophylluui. 



The material of Flahmdtia palmata, being dry, was not good 

 enough to enable an accurate figure of the entire cystocarp to be 

 made. It agrees in all respects with the figure by Dr. Bornet in 

 his paper on Schousboe"s Alg» (Alg. Schousb. Mem. Soc. Sci. Nat. 

 Cherb. t. xxviii. 1892, pi. h. fig. 5). My thanks are due to Mr. 

 Batters for his kind help in determining several species. 



