MARINE ALGJE OF BEAUFORT, N. C. 



393 



In February we find the last reduced plants of Codium tomentosum (C. decorticatum 

 having disappeared earlier) and of Chondria dasyphylla. From this time the flora 

 consists entirely of perennial and spring species. Porphyra has attained a large size; 

 Enter omorpha linza has appeared; and Enteromorpha prolifera, Ectocarpus confervoides, 

 Petalonia, Porphyra, Agardhiella, Gracilaria multipartite, and Grinnellia are the principal 

 species composing the flora. 



In March, the algae are scarcer than at any other time during the year, but the 

 perennial and spring species already mentioned are present without change, except that 

 small plants of Leathesia have made their appearance. 



During April the spring flora attains its greatest development. The dominant form 

 throughout the harbor and along all the shores is Ulva lactuca, which occurs on all rocks 

 and forms large masses lying free on the bottom. Closely rivalling this are Entero- 

 morpha prolifera and Porphyra growing on all rocks and posts throughout the harbor. 

 These three species are extremely abundant everywhere, but in limited areas they are 

 surpassed by Polysiphonia nigrescens and Ceramium strictum. The species occurring 

 here at this time may be grouped as follows : 



ABUNDANT. 



Lyngbya confervoides. 



Enteromorpha linza. 



Enteromorpha prolifera. 



Ulva lactuca. 



Ectocarpus confervoides. 



Petalonia fascia. 



Myrionema strangulans. 



Leathesia difformis. 



Fucus vesiculosus. 



Porphyra leucosticta. 



Acrochaetium virgatulum. 



Gelidium crerulescens. 



Agardhiella tenera. 



Gracilaria multipartita. 



Champia parvula. 



Lomentaria uncinata. 



Grinnellia americana. 



Chondria tenuissima var. baileyana. 



Polysiphonia nigrescens. 

 Dasya pedicellata. 

 Ceramium strictum. 



OCCURRENCE LIMITED. 



Enteromorpha flexuosa. 

 Enteromorpha intestinalis. 

 Chsetomorpha melagonium f . rupincola. 

 Rhizoclonium riparium. 

 Cladophora flexuosa. 

 Bryopsis plumosa. 

 Ectocarpus siliculosus. 

 Stilophora rhizodes. 

 Sargassum filipendula. 

 Bangia fusco-purpurea. 

 Acrochaetium corymbiferum. 

 Gelidium crinale. 

 Gymnogongrus griffithsise. 

 Hypnea musciformis. 



Young plants of several species were observed at this time. Several specimens of 

 Codium 3 to 12 mm. tall were found on shells in the clearer, deeper water north of the 

 laboratory. Fucus showed, in addition to the large plants, many germlings 2 to 3 mm. 

 tall. Small plants of Chondria dasyphylla also were observed. 



Besides the germlings of Fucus, many large plants up to 14 cm. tall were present. 

 These were entirely without fruit. Ulva, Enteromorpha prolifera, Lomentaria, and 

 Champia grew more abundantly and to a larger size than in summer. Fruiting plants 

 of Hypnea i to 6 cm. tall were observed, all of these being tetrasporic. 



During May the spring species begin to disappear, some of the plants showing signs 

 of disintegration. Enteromorpha linza, E. prolifera, Chcetomorpha melagonium f. rupin- 

 cola, Stilophora, Bangia, Porphyra, Dasya, Polysiphonia nigrescens, Grinnellia, and 

 Ceramium are, however, still present. Hypnea has now attained its summer condition, 



