1' . Børgesen : Rhodophyceæ of the Danish W. Indies. 



389 



Julius Kütz., Tab. phycoL, vol. 18, pi. 93), Rh. linearis J. Ag., 

 Rh. ligulata 'Zandird. etc. may be pointed out. 



The plant was found at a depth of about 10—15 fathoms 

 of water. It was growing, apparently rather abundantly, in the 

 sound between St. Thomas and St. Jan as a component of the 

 very rich algal vegetation found here. 



St. Jan: Found in several places in the sound between this island 

 and St. Thomas: off Cruz Bay, near Great St. James, off Hermitage, off 

 Annaberg. 



Coelothrix nov. gen. 



Frons rigida, filiformis, ex numerosis filamentis arete con- 

 junctis orta, tubulosa, in interiori parte cava, irregulariter ramosa, 

 ramis sparsis, interdum secundis et inter se conglomeratis, inter- 

 dum anastomosantibus cæspites densos formantibus. 



Frons ex duobus stratis composita, exteriori cortice uni- 

 strato, cellulis minoribus densis, interiori celluhs gradatim ma- 

 joribus, rotundatis-polygoniis, cavitatem versus glandes sparsas 

 gerentibus. 



Tetrasporangia apici 

 inflato ramorum inha- 

 bita. 



1. Coelothrix irregularis 



(Harv.) 



Cordylecladia? irregula- 

 ris Harv., Nereis Bor.-Am., 

 part II, p. 156. 



When Harvey re- 

 ferred this plant to the 

 genus Cordylecladia he 

 put, no doubt correctly, a 

 query behind the name as 

 the structure of this plant 

 differs greatly from that 



of the type species : Cordylecladia erecta, a transverse section of 

 which being very like that of Gracilaria. Considering the struc- 

 ture of the thallus, especially since this is hollow as already pointed 

 out by Harvey, and the glands found upon the cells facing the 



Fig. 373. Coelothrix irregularis (Harv.). 



Part of a plant. Below two branches with 



anastomose. (About 4:1). 



