144 NEW ALG.E FROM CEYLON. 



Thuretia, etc., Lave been discovered iu the warmer seas. Of these, 

 Lictyurm alone (wliich is common in Ceylon) has hitherto been re- 

 corded as inhabiting the Indian Ocean, it having been found by 

 Belanger, and afterwards by Dr. Wight, near Cape Comorin ; the rest, 

 with the exception of EalopUegma^ which has a West Indian species, 

 having been supposed to be confined to the Southern Ocean, and chiefly 

 to the shores of Australia. 



I have now the pleasure to introduce to botanists, from the south 

 coast of Ceylon, not only new species of Claudea and of Martensia, 

 but also to add to this interesting group a new genus, wMch yields^to 

 none of its associates in beauty and delicacy of structure. This genus 

 I wish to dedicate to John Van Voorst, Esq., F.L.S., the well-known 

 Natural History publisher, who, though not himself a working natural- 

 ist, is a notable instigator of work in others, and, as the originator of 

 a noble series of Monographs illustrating the Natural History of Great 

 Britain, deserves the respect and thanks of his countrymen. The crest 

 of the Van Voorsts (a family of no mean standi] _ 

 mermaid^ from whose toilet the exquisitely delicate lacework now to be 



V ■ 



described may have been stolen; and I have peculiar pleasure in asso- 

 ciating with so charming a sea-plant the name of a friend for whom, 

 personally, I have a cordial regard and esteem. 



Vanvookstia, Harv. (nov. gen.) 



Frons explanata, vane lobata, decumbens, facie inferiore radiculis ad- 

 hterens, reticulatim clathrata. Reticulum ex costis costulisque cellu- 

 losis compresso-planis iteratim secunde ramosissimis verticaliter ana- 

 stomosantibus formatum. Ceramidia ovata, in reticulum sessilia, 

 sparsa, intra pericarpium membranaceum, poro pertusura, sporas 

 pyriformes e placenta basali egredientes, pedicellatas foventia. Tetra- 

 spor^B suhbiseriatae, in trabeculis ultimis reticuli immersae, — Alga 

 elegantisdma^ gregariay algas varias prorepenSy Uvida^siccitate Icete pur- 

 purea ; substantia recentis cartilagineay rigida, fragilisy mox in aqua 

 dulci eniolliens et in gelatinam deliquescens, Structura laxe cellulosa. 



1. Vanvoorstia spectaiiUs. (Tab. V.) 



Hab. Growing on corallines and various small algae in rock-pools, on a 

 coral bank, in 2 or 3 feet water, three miles west of Belligam, south 



coast o 

 Fronds 



w. m H, 



