F. Borgesen: Phæophyceæ of the Danish W. Indies. 



45 



practice and he proposed three groups. His classification ougtht 

 now to be essentially modified after the examination of M me Weber. 



Referring for detail to the paper itself I shall only here 

 mention what has a special interest concerning the West Indian 

 species. Thus it is pointed out that J. Agardh has been wrong 

 in referring Padina gymnospora, P. Antillariim and P. variegata 

 to P. Durvillaei and that Hauck also has been mistaken when 

 he refers P. gymnospora Kütz., distributed in the exsiccata of 

 Hohenacker (no 515) to Padina Commersonii. To be sure 

 M lle Vickers had even in 1905 Padina gymnospora and P. variegata 

 in her "Liste des Algues marines de la Barbade 1 ' but she gives 

 no reasons for taking up these species. Of course it is most 

 probable that she has got some information from Dr. Bornet. 



The West Indian forms collected by me I have referred to 

 the two species of Kützing : P. gymnospora and P. variegata and 

 further to a new species. 



1. Padina Sauctae Crucis nov. spec. 



Frons membranacea, 10 — 15 cm alta, pluries subfissa, seg- 

 ments terminalibus flabellatis, duobus cellularum stratis composita, 

 rhizoideis numerosissimis e parte basali angustiore ortis adfixa. 

 Pili in zonas concentrales ordinati, sori tetrasporangiorum supra 

 alternas series pilorum concentrice distributi sunt. 



As pointed out in the diagnosis this species is characterized 

 by having a distromatic thallus through its whole length (comp. 

 Fig. 21 b, c, e), by the di- 

 stribution of the tetraspor- 

 angia, the latter occurring 

 in broad series along the 

 upper side of every second 

 row of hairs (Fig. 28) and 

 by the presence of a well- 

 developed indusium covering 

 the tetrasporangia-sori (Fig. 

 27 d, e). 



The plant reaches a 

 height of about 10 — 15 cms 



and is somewhat incrusted „ F 'g- , 28 - Padina St. Crucis nov. spec. 



Part of the thallus seen from above show- 

 with chalk upon the lower j ng the mutual arrangement of the series 

 surface , hence the dried of hairs and tetrasporangia. 



plant has here a whitish 



colour with dark brown rings, while the upper side is yellow 

 brown with darker rings. 





