MARINE ALGJE, OF BEAUFORT, N. C. 509 



five, in the older portions surrounded by one or more layers of smaller secondary cells and always inclosed 

 by a layer of small, cortical cells; tetrasporangia numerous, borne in linear-lanceolate stichidia attenuate 

 at the apices; cystocarps urn-shaped, often excentric, usually single, rarely 2 to 3 together, borne near 

 the apices of short lateral branches; texture soft gelatinous-cartilaginous, flaccid; color light to dark 

 purplish red; tetrasporangia, antheridia, and cystocarps borne on separate plants; sexual and asexual 

 generations alternating regularly in the life cycle. 



New England to West Indies; Canary Islands; Mediterranean. 



Throughout harbor, and on Fort Macon and Shackleford jetties, Beaufort, N. C., 15 to 45 cm. below 

 low-tide level, very abundant April, 1908, abundant May, 1907, few specimens on coral reef offshore, 

 May, 1907. Collected during the winter and spring 1908-9, as follows: Fort Macon jetty, December, 

 one small fragment; April, large, fruiting; May, small, battered; Bogue Beach, February, sterile; 

 March, fruiting; April, large, fruiting. Few specimens Bogue Beach, July, 1903, and September, 1904; 

 few small specimens attached to stem of Leptogorgia virgulata on Fort Macon jetty, August, 1904. 

 One specimen about i cm. tall on shell in sound near inlet, Pawleys Island, near Georgetown, S. C., 

 August, 1909. 



This species will not be mistaken for any other, being easily recognized by its dense covering of 

 capillary, dichotomous filaments. In this region the species seems to appear in occasional specimens 

 during the winter, reaches its maximal development in April, and almost or entirely disappears by 

 June. Further study is needed to show how it survives from one spring to another, since the occasional 

 specimens observed at other seasons have not been found with sufficient regularity to account for the 

 maintenance of the species. 



Family 5. CERAMIACE/E (Bonnemaison) Naegeli. 



Frond terete or flattened, often filamentous, richly laterally or dichotomously 

 branched, usually erect, sometimes partially or almost entirely horizontal, rarely para- 

 sitic, structure various, usually composed of naked or more or less corticated filaments; 

 tetrasporangia occurring singly or in groups, in special branches or scattered over the 

 frond, external or sunken in the cortical layer, usually triangularly, sometimes cruci- 

 ately, divided; antheridia scattered over the thallus in various positions, bearing numer- 

 ous crowded spermatangia ; carpogonia usually closely associated with cells which, 

 after fertilization, produce the auxiliary cells, forming definite procarps of various 

 forms, external, scattered over the thallus or occurring in definite regions, often having 

 two auxiliary cells associated with one carpogonium ; cystocarps external or more or less 

 embedded in the cortex, conspicuous, sometimes occurring in pairs, often having two 

 gonimoblasts associated in a single cystocarp, naked or inclosed by special filamentous 

 branchlets forming a more or less lax pericarp, gonimoblast arising from a basal pla- 

 centa, sometimes compact, usually divided into several more or less conspicuous, usually 

 rounded lobes, consisting of richly branched filaments forming carpospores from nearly 

 every cell. 



Nearly 400 species, in all seas, especially in warm regions; two species reported as 

 terrestrial. 



KEY TO GENERA. 



a. Thallus consisting of monosiphonous filaments entirely or almost entirely without cortex b. 



b. Thallus consisting of erect, laterally branched, filamentous branches arising from 



horizontal filaments; cystocarps terminal , bearing two gonimoblasts. . i. Spermothamnion (p. 510). 

 bb. Thallus erect, consisting in part of long barrel-shaped or obovoid cells in moniliform 



filaments; cystocarps terminal, sometimes appearing lateral at the nodes. 2. Griffithsia (p. 511). 

 bbb. Thallus erect, main filaments often corticated be\ow with descending rhizoidal fila- 

 ments; cystocarps lateral, sessile 3- Callithamnion (p. 511). 



