Collins and Howe: Species of Halymenia 173 



peculiarities, the outline of the central node or gangHon in H. 

 bermudensis is, when viewed through the cortex, more lobed, 

 stellate, or brachiate, and less orbicular or rotate than in H. 

 floridana. 



J. Agardh founded Ilalymenia floridana on several specimens 

 sent to him from Florida by Mrs. Floretta C. Curtiss, and he 

 appears to have put certain specimens of the same thing, or of 

 the typical thing, in the " Kallymenia reniformis" cover in his 

 herbarium. Specimens of it, collected by A. H. Curtiss at Gil- 

 bert's Bar, Florida, were distributed by Curtiss with a printed 

 "Algae Floridanae" label under the name "Kallymenia reni- 

 formis J. Ag.," from which plant it differs greatly in structure. 

 Halymenia floridana and H. hermndensis, however, differ from 

 typical Halymenia {H. Floresia) in their firmer subparenchymatous 

 cortex, in their much firmer, non-deliquescent and scarcely 

 gelatinous outer walls of the superficial cells, and in the striking 

 development of the medullary ganglia. It is possible, as has 

 already been hinted by one of us,* that more critical studies, 

 especially of the development of the cystocarps (abundant in 

 H. floridana), may furnish adequate grounds for the establishment 

 of a new generic group which would include not only Halymenia 

 floridana and H. bermudensis but also the Peruvian Sebdenia 

 heteronema. J. Agardh placed Halymenia floridana in his section 

 Halarachnion of the genus Halymenia, and De-Tonif has ranged 

 it, with a question mark, under the generic name Halarachnion, 

 but the type of Halarachnion (H. ligidatum) has no medullary 

 ganglia comparable with those of Halymenia floridana and it 

 differs also in the structure of the cortex. 



Halymenia bermudensis may or may not adhere to paper when 

 dried under pressure. 



Halymenia Gelinaria sp. nov. 



Thallo roseo-vinaceo vel vinaceo-purpureo, brevi-stipitato; 

 stipite a disco basali orto, inferne subtereti, superne cuneato; 

 fronde plana, levi, nee nitente, membranacea vel subcarnosa, 

 plerumque maxime gelatinosa, 60-600 ix crassa, suborbiculari, 

 oblonga, ovata vel cuneato-obovata, latitudine 5 cm. usque 6 dm., 



* Howe, Mem. Torrey Club 15: 165. 1914. 

 tSyll. Alg. 4: 1655. 1905. 



