BOTANICAL 



OAKDt.N 



F. Børgesen: Rhodophyceæ of the Danish W. Indies. 



145 



be possible that, if fertile specimens are found, the West-Indian 

 plant will prove to be a different species, I queried it therefore 

 and also, because its colour is darker than the colour of P. con- 

 chicola. It resembles, as already stated, P. conchicola in anato- 

 mical structure and differs from P. simulans, in adhering firmly 

 to the substratum. From P. rubra it is easily known by its long 

 apical cell. 



Found at St. Croix, White Bay, in shallow water (No. 15371, 15461, 

 15851). In alcohol and dry specimens. 

 Geogr. Distrib. : Red Sea. 



7. Peyssonnelia (Eupeyssonnelia) 

 polymorpha? (Zan.) Schm. 



Schmitz, in Falkenb., Alg. Neap., 1879, 

 p. 264. De Toni, Syll. Alg., vol. IV, sect. 

 IV, 1905. p. 1701. 



Lithymenia polymorpha Zanard., Icon. 

 Phyc. Adriat. I, 1860, p. 127, tab. 30. 





% 



Fig. 149. Peyssonnelia con- 

 chicola Pice, et Grun. Cross- 

 section through nemathecia 

 with tetraspores. (260:1). 



The specimen No. 1966 belongs 

 probably to P. polymorpha, but it is 

 too small to name it with certainty. 

 It was collected with the dredge and 

 we know that P. polymorpha prefers 

 deeper water. M™^ Lp:moine ^) has de- 

 scribed this alga from various locali- 

 ties in the Mediterranean, and a va- 

 riety of it has also been found at 

 the island of Amirante^) The speci- 

 men from St. Thomas has the typical brick-red colour of the 

 species, the hollow crust is entirely loosened from the substra- 

 tum and the anatomical structure is very much like that of 

 P. polymorpha. The specimen bore nemathecia with unripe 

 carpospores. 



Found at St. Thomas near the West-End of the island off Thatch 

 Bay in a depth of about 14- 16 fathoms (No. 1966). Dry specimen (by Dr. 

 Th. Mortensen). 



Geogr. Distrib.: Mediterranean Sea. 



1) Mme p. Lemoine et M. Mouret, Sur une algue nouvelle pour la France. 



Bull. Soc. Bot. 1912, p. 356. 

 ^) A. Weber-van Bosse, Rhodophyceæ of the "Sealark" Exp. Trans. 



Linn. Soc. 1913, p. 139. 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1 (1917). 10 



