V. CORALLINACE^. 87 



Hab. Monterey, Decakne. St. Francisco, Bar-day. (v. s. in Herb. T. C. D.) 



The St. Francisco specimens are three or four inches long, tvnce or thrice irregu- 

 larly forked, the ultimate divisions dichotomous, the lower ones ii'regularly pinnated 

 with numerous, lateral, simple branches. All the artioilations are strongly com- 

 pressed, the sides depressed, the central part raised and rib-like ; the lower ones of 

 the larger branches as well as of the lower divisions are cuneate, the upper gradu- 

 ally broader and more cordate, with much produced but rounded upper angles ; the 

 terminal articulations narrow. Conceptades large, on my specimens generally in 

 pairs on each articulation, but sometimes four or five on the lower ones. 



I have not seen any authentic specimen of the plant of Decaisne, who describes 

 it thus ; " dichotomous ; articulations compressed, and frequently cuneate, and 

 generally furnished with four conceptades on each face :" chai-acters which do not 

 strictly apply to my specimens, which nevertheless, I hesitate to describe as new. 



5. AiiPHiROA (Arthbocardia) tuberculosa, Endl.; " dichotomous ; dirty white or 

 rosy violet ; lowest articulations subterete, once and half as long as broad, upper 

 dilated, more or less deeply obcordate, uppermost sub-approximate, irregularly 

 cuneate-rhombic, sometimes linear, tuberculated at the back and margin ; some of 

 the tubercles perforated ; branches scattered, subsimple, clavate or emarginate at 

 the apex." Kiitz. Sp. Alg. p. 704. Corallina tuberculosa^ Post, and Rupr. III. p. 20, 

 t. 40, fig. 100. 



Hab. Island of Sitcha, Postels and Ruprecht. 



I have seen no specimen of this or of the preceding species. 



MELOBESIA. Lamour. 



Frond attached by its lower surface or free ; either flattened orbicular, sinuated 

 or irregularly lobed ; or cylindrical and branched ; never articulated, coated 

 with a calcareous deposit. Concq)tades conical, scattered over the surface of the 

 fronds or partly immersed, furnished with an apical pore, and containing in the 

 base of the cavity a tuft of erect, oblong, four-parted spore-threads. 



The North American species of this genus have not yet been carefully examined 

 or collected. Probably several occur along the coast, and Avill be found eitlior 

 encrusting tidal rocks ox' stones, or lying at the bottom of harbours in from five to 



