— 145 — 



St. Jan. Off Hermitage in the sound to the north of this 

 island and Tor tola in a depth of about 30 meters. It was earlier 



Fig. 11. Halimeda gracilis Harv. var. opuntioides no v. var. 



About 1 : 1. 



found at St. Thomas by the Challenger Expedition and Mrs. 

 Gepp tells me that forms from this island exactly like mine are 

 in the British Museum. 



Bryopsis. 



Four to five years ago I examined my material of this genus 

 and came at that time to the conclusion that in every case my 

 material from the Danish Islands only contained two species, viz.: 

 Bryopsis plumosa Huds. and Bryopsis hypnoides Lamx. 



To be sure specimens occur, some of which show great like- 

 ness with Br, pennata Lamx., others with Br. Harveyana J. Ag. 

 and Br. Leprieurii Kütz., but often in the same specimen we find 

 transitional forms to the one or other of these forms. Bryopsis 

 pennata is characteristic and separated from Br. plumosa by having, 

 as J. Agardh writes (Till Algernes Systematik, VIII, Siphoneæ, 

 p. 23): "frondibus crectiusculis subsimplicibus, superne distiche phi- 

 mosis, pluma initiali ambitu lineari lanceolata, ramentis distichis 



Botanisk Tidsskrift. 31. Bind. 10 



