238 



Delesseriaceae. 



Hypoglossum tenuifolium (Harv.) J. Agardh. 

 f. Schoonhoveni n. f. Curaçao. 



This alga is characterized by the big médian sorus instead 

 of two sori (flg. 6), one on each side of the midrib as we 

 usually find in Hypoglossum. One médian sorus is typi- 

 cal for Delesseria, and I stould talïe this alga as a Deles- 

 seria if it had not so many characteristics in common 

 with Hypoglossum and specially with H. tenuifolium. The 

 new branches are developed on the midrib and that con- 

 sists of one central and two cortical rows of cells (fig. 7. 8.) 

 However the alga differs from the typical spécimens of 

 Hypoglossum tenuifolium from Key-West by its big médian 

 sorus, stouter frond and leaves not blunt at the top but 

 often lengthened in a narrow band (fig. 9) from which 

 new branches issue. I wish to distinguish it as a new 

 form for which I propose the name of Schoonhoveni in 

 honour of captain Schoonhoven, who gathered it for me 

 at Curaçao. 



Zellera Boekeï n. sp. 



Koot and . stem unknown. 

 Upper part of plant consisting 

 of a dichotomically branched, 

 broadly winged axis, that carries 

 unilatéral and dorsally inserted 

 winged branches or leaves; 

 thèse carry branches of second 

 order and thèse again branches 

 of third order. Ail ramification 

 strictly unilatéral and dorsal. 

 Cystocarps on the midrib, 

 pitcher-shaped. Tetraspores 

 unknown. St. Eustatius 25 

 fathoms. leg. Boeke. 



Out of a depth of 25 Zellera Boekei n. sp. (enlarged). 





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