OF ARTS AND SCIENCES. 373 



ad ramellos externe insertae, nudae. Forma et substantia P. Conlteri 

 similis, ramificatione ultimarum piunularum et insertione fuvellarum 

 diffi-rt. — California, Oregon. 



It has long seemed to me that the specimens of Mlcrocladia Conl- 

 teri distributed bj collectors differed very much in aspect, and that at 

 least two different varieties could be distinguished. 31. Californica, in 

 fruit, is easily distinguished from the typical specimens and figure of 

 M. Coulteri by the favellae which are borne on the outer side of the 

 ultimate ramuli, and are always destitute of the involucre which is 

 found in M. Coulteri. M. Calif ornica resembles in habit Pulysiphonia 

 Woodii, which M. Coulteri does not. 



301. MiCROCLADiA. BOREALis, Rupr. California, Oregon. 



302. Centroceras clavdlatum, Ag. Key West, California. 

 *303. Centroceras Eatonianum, n. sp. Frons capillaris, iner- 



mis, pinnata. Pinnae distichae, bi-tripinnatae, segmenta terminalia divar- 

 icata. Geniculae constrictsE. — Oregon, Mr. E. Hall ; California. 



This species bears more resemblance to a Ceramium than to G. 

 clavulatum, from which it differs in being pinnate instead of dichotomous 

 and constricted at the joints, which are smooth and destitute of spines. 



304. Ceramium nit ens, Ag. Key West. 



305. Ceramium rubrum, Ag. Everywhere on the east coast, 

 but not yet known, with certainty, on the west. 



306. Ceramium Deslongchampsii, Ch. Common on rocks. Na- 

 hant, Mass., northward. 



The species called by Harvey Ceramium Hooperi was founded on 

 poor specimens of C. Deslongchampsii, a common European species. 

 Harvey mentions the " dark purple endochrome " as peculiar to C. 

 Hooperi. It is, however, found in C. Deslongchampsii, The " root- 

 like filaments " are found in all the procumbent Ceramia and Poly- 

 siphonicB. Harvey says that the plant is one or two inches high. I 

 have collected it in Portland harbor nearlv five inches hish. 



307. Ceramium diaphanum, Roth. Certainly not common on the 

 east coast, although I have found what I think must be this species at 

 Nahant, Mass. — Key West and California specimens look more like 

 the typical European specimens than do the New England specimens. 



*308. Ceramium strictum, Harv. New Haven, Noank, Conn.; 

 Wood's Hole, Mass. — Nine-tenths of the American specimens of C. 

 diaphanum belong to this species, which is much more slender and 

 somewliat corymbose. 



309. Ceramium TENUtssiMUM, Lyngb. Key West, Harvey. 



310. Ceramium fastigiatum, Harv. Long Island Sound, Massa- 



