THE MARINE ALG.E OF NKW ENGLAND. 79 



A >;«Mius of niinuti' ;il;;a' which tonn sinull brown spots on other plants. The si»ecio.H 

 arc uhiqiiitons, but the specitie eharacters are not well delined, an*! a good share of the 

 dejurilMMl species are merely ditlerent forms of the very common M. vulf/are. Tho two 

 ditferent kinds of sjMirangia are sometimes found together, but are usually on ditVerent 

 plantxS. The genus is most nearly related to Jial/sia, which may be said to be a Myri- 

 onema in whieh the lu»ri/ontal layer has bee»»me nnich thickened, and tlie vertical lila- 

 ments, with the interspei"sed sporangia, instead «)f covering the surface uniformly, have 

 btH»n eonlined to certain circumscribed imrtions. The two genera are closely con- 

 nected by L'ulfnid clavata. Cm., which was tirst di'scribetl as a Myrionema by Carmichacl. 

 In lialjxui the vertical lilaments must be considered to be jKiraphyscs, and perhaps 

 those of Mifrionema should also bo so considered. 



M. VULGARE, Tliur. (.Y. strangulans, Givv.; riiyc. JJiit., PI. 2S0.— 

 M. puticti/ormCy Ilarv., Pliyc. Brit., PI. 41 h. — }[. maculi/ormc. Kiitz., 

 Tab. Phyc, Vol. VII, PI. 93, Fig. 2.) 



I'roiuls .04-8'"™ ill tbickness, vertical tilaiiient^s (parapbyscs) sligbtly 

 iliib-sbaped and moniliform, uuilocular sporangia oval, .010-27'"'" broad 

 by .03-4'"'" long, sessile or borne on sbort pedicels. 



I-^verywbere common on various algie. 



in Le Jolis's Liste des Algues Marines de Cherbourg, Thuret is quoted as authority 

 ioT uniting several of the species of Alifriouema of Harvey and Kiitziug. The alleged 

 specific distinctions are plainly nothing but niodilicatious of the same species, dependent 

 on the place of growth. When found on small cylindrical fronds, as in some Entero- 

 morpho', the Myrlonema surrounds the frond and constitutes the M. straugulansoli Grexillc, 

 and when growing on tlat surfaces the form known as J/, punctiforme is found. lu 

 this country the unilocular sporangia are very common, but we have never seen the 

 plurilocular sporangia, while in the next species the plurilocular sporangia are more 

 ninueroiLs, although both kinds are found. 



M. Leclancherii, (Cbauv.) Ilarv., Pbyc. Brit., PI. 41 a. PI. G, Fig. 5. 



r'ronds .06-10"^" in tbickness, vertical filaments (parapbyses) cyliu- 

 diical, unilocular sporangiti oval, plurilocular si)orangia .008-10'"™ broad 

 by .023-30'"'" long, ovate, oblong, sessile or on very sbort pedicels. 



On Rhodymenia palmata. 



Gay Head, Mass. ; Europe. 



This species fonns rather larg.T spots than the last on the common dulse. That it 

 is really distinct from M. rnlgare admits of doubt. There appears to be a ditlerence 

 in the paraphyses of the two. but such ditferences cannot be considered of much value. 

 We have found both unilocular and plurilocular sporangia in the present species, 

 but unfortunately have not preserved measurements of the latter. The plurilocular 

 sporangia are sometimes very numerous and stand side by side without intervening 

 paraphyses. 



Family LEATIIKSIE.E. 



Fronds lubricous or gelatinous, indefinitely expanded or irregularly 

 globose, consisting of a basal portion, composed of irregularly branch- 

 ing filaments formed of large, colorless cells, and a cortical portion of 

 clo.sely i)acked, sbort, colored filaments; panipliyses often present; 



