— 138 — 



short note about this matter by Collins at the place quoted above, 

 I think that Collins has not examined the question about the 

 nomenclature so very much in detail but used the name which has 

 been most in use in America, namely Halimeda tridens. 



Ho we refers four species to his Halimeda tridens group, namely, 

 H.favulosa Howe characterized by very large peripheral utricles ; a form 

 like this I have not found in the Danish West Indies. Further besides 

 the typical H. incrassata he considers the forma monilis as a species 

 and describes finally the new species H. simulans. As distinctions 



Fig. 4. Halimeda tridens (Ellis et Solander) Lamx. 



Tree different forms from Krause's Lagoon (my collections nr. 1484). About 2 /3. Compare text. 



between the species Howe also, lays stress upon histological cha- 

 racters, namely the peripheral utricles, as after Howe these in H. 

 tridens are 49 — 77 p in average maximum diameter while in H. mo- 

 mie and H. simulans they are 30 — 40 jn in average maximum diameter, 

 these two species being kept separated by the forms of the joints 

 which are mostly subterete in the first mentioned, discoid in 

 the last. 



Having now examined a very large number of specimens in 

 my collection I willingly admit that these characters in the different 

 forms very often agree with what Howe has found, in that the 



