V. CERAMIACE^. 241 



or fours, densely crowded at the tips of the branches, opposite, very erect, pinnate ; 

 pinnaB opposite, very erect, cylindrical, obtuse, scarcely tapering ; articulations of 

 the stem and branches variable, of the ramuli three or four times as long as broad ; 

 tetraspores terminating the lower, abbreviated pinnte of the ramuli, cruciate. ./. 

 Ag. Sp. Alg. 2, p. 27. Harv. Phyc. Brit t. 164. Kiitz. Sj?. Ag. p. 549. /3 tejme ; 

 slender, with more distant, less compound and shorter ramuli. 



Hab. Xew York Bay, at Red Hook, Messrs. Walters and Hooper, (v. v.) 



Tufts dense, globose and somewhat level-topped, an inch to an inch and half high. 

 Filaments capillary, alternately divided, but not much branched, the branches erecto- 

 patent, the upper ones shorter and closer together, the lower distant. Ramuli at 

 every node two opposite or four in a whorl, half a line to a line in length, densely 

 crowded at the ends of the branches, rarely more than simply pinnated. Pinna; 

 very erect, opposite or, by suppression of one, alternate or secund, the inner pinnse 

 being most commonly abortive, cylindrical, or slightly tapering to an obtuse point. 

 Internodes of the stem and branches four to six times as long as broad, of the upper 

 branches twice or thrice, of the ramuli about thrice as long as broad. Fruit rare 

 and not yet observed on American specimens. Colour, a brownish-red, inclining- 

 sometimes to purple. Substance soft, but not very flaccid. It adheres closely to 

 paper in drying. 



As yet I am only aware of the single American station for this species above 

 given. Mr. Walters's specimens of both varieties are very similar to those found 

 in the South of England. 



Sect. 5. Repentia. Fronds {of small size) rising from prostrate creeping matted 



threads. Favellai involucrate. 



16. Callithamnion Turneri, Ag. ; filaments (densely tufted) rising from pros- 

 trate, creeping fibres, simple or repeatedly branched, once or twice pinnated with 

 opposite or alternate spreading, simple ramuli ; articulations very variable in 

 length, 5 — 10 times as long as broad ; tetraspores clustered, sub-racemose or 

 corymbose, on abbreviated ramuli ; fixvellaj involucrate. /. Ag. Sp. Alg. 2, p. 23. 

 Harv. Phyc. Brit. t. 179. Klitz. Sp. Alg. p. 649- Conferva Turneri, Dillw. t. 100, 

 E. Bot. t. 2339. /3 variabile ; branches and ramuli alternate or secund. Callitham- 

 nion variabile, Ag. Cal. roseolum ? J. Ag. Sp. Alg. 2, p>. 21. Conferva repens, Dillw. 

 18, E. Bot. t. 1608. 



Hab. Parasitical on various Algte. Rhode Island, on Cladostephus, Prof. J. W. 

 Bailey. ^ Boston, Dr. Durkee. Key West, W. H. H. (v. v.) 



Fdaments rising from decumbent, creeping, matted fibres, densely tufted, half an 

 uich to an inch in height, capillary, flaccid, sub-simple, or once or twice oppositely 

 branched ; stem, branches and ramuli all nearly of the same diameter, and all pellu- 



VOL. IV.— AKT. 5. ' I I 



