6 THE VOYAGE OF H.M.S. CHALLENGER. 



Caulerpa clavifera, K. A. Agardh. 



Caulerpa clavifera, K. A. Agardh, Sp. Alg., L p. 437 ; Dickie in Journ. Linn. Soc. Lond., xiv. p. 358. 

 Chauvinia clavifera, Kiitz., Sp. Alg., p. 498. 



St Paul's Rocks. Moseley. 



" The leaves, commonly so called, are longer in proportion and more densely imbricated 

 than usual ; in these respects the specimens collected by Mr Moseley are nearly allied to 

 Caulerpa Icetevirens, Mont., from Toud Island, Southern Ocean, of which I have not seen 

 any authentic specimens. It appears to be plentiful and of large size, and is used by 

 Sterna stolida to form its nests." — Dickie. 



Ulvace^e. 

 Prasiola minuta, n. sp. ? 



Prasiola minuta, n. sp. ? Dickie in Journ. Linn. Soc. Lond., xiv. p. 358. 



Thallo e basi angustata lineari-lanceolato ; cellulis subquadratis, in basi 1-3, sursum 

 5-6 seriatis. 



A very miuute species, only detected by use of the microscope ; no example quite entire 

 could be seen ; diameter of the broadest frond = 0'0014 of an inch. 



St Paul's Rocks. — In stagnant rock-pools among fine mud — Moseley. 



OSCILLATORIACE^E. 



Oscillaria sordida, n. sp. ? 



Oscillaria sordida, n. sp. 1 Dickie in Journ. Linn. Soc. Lond., xiv. p. 358. 



Trichomatibus sordide viridibus, ad apicem obtusis, articulis quam diameter (0-0004) 

 quadruplo brevioribus, ad genicula paulo contractis. 

 St Paul's Rocks. Moseley. 

 Sparingly and very fragmentary along with the Prasiola. 



Palmellace^e. 

 Protococcus afrlnis, n. sp. ? 



Protococcus affinis, n. sp. 1 Dickie in Journ. Linn. Soc. Lond., xiv. p. 358. 



Protococcus sordide viridis, cellulis globosis (diam. = 0-0002 in.-0-0004 in.), in stratum 

 tenue cumulatis. 



St Paul's Rocks. Moseley. 



" It seems to be nearly allied to Protococcus viridis, Ag. It forms a dull green coat 

 upon Btalactitic masses among guano in sheltered crevices." 1 — Dickie. 



"Tins is doubtless similar to the matter alluded to by Mr Darwin 'as resembling some of the branched 

 species i of mill.porc.' It does not effervesce in acids ; and Mr Darwin found it on the Abrolhos Islands anion" 

 birds' dung."— Dickie. ° 



