Tin: MAKINE ALCJ/K OF NEW ENGLAND, IGl 



arc in the soinowiiat swoIUmi tips of t\w frond. The present species is usually found 

 Avaslu'd ashon' from »leep wator, l»ut on tlu' northrrn coast is found also in dtt p tide- 

 ])ools. "NVhcn dri«'d it lu'coinrs brittle and <1(M's not atllHTc to pajxr. 



SrHOKDHU sriLKKOCOCCOlDEyK. 



» 



Fronds cylindrical or mcinbiaiiaccous, substaniM' often very delicate; 

 antheridia lbrniin«j: snporticial patches or occasionally contained in 

 sunken cavities; tetraspores cruciate, zonate, or tripartite, often col- 

 lected in spots (sori) on the surface; cystocarps external, hemispherical 

 or Hask-shai)ed, spores arranged in nionilifoiin lilanieiits, w jiich radiate 

 from a basal placenta, carpostome distinct. 



The i)resent sul»ord«'r is by Ajjardli and some other writers divid<'<l into two, the 

 SphaTOcoccoideiv, which include rather coai'se cart ilaj^inous aljj;a', which anr cylindrical 

 or somewliat compressed, but hardly membranaceous, and the JklcsHeriea; which arc 

 rosy-red and of delicate texture and distinctly nu'mbranaceous. The fruit, however, 

 is very similar iu both groups. The spores are arranged in subdichotomous iilaments, 

 which radiate from a basal placenta, which in sonu; genera, as Crracilaria, projects far 

 into the cavity of the cystocarp. The suborder diti'ers from the lihodymeniia- iu that 

 the moniiiforni arrangement of the sporiferous Iilaments is preserved even at matu- 

 rity, and the lilanu'uts are distinct from one another and not held together ])y a gelat- 

 inous envelope. It must, however, be admitted that there are genera which seem to 

 indicate a close relation between the two suborders. 



GRIXNELLIA, Harv. 



(Named in honor of Mr. Henry GrinneU, of New York.) 

 Fronds rosy-red, occasionally purple, delicately membranaceous, with 

 a slender percurrent midrib, composed of a sin^^de layer, at the midrib 

 of several lasers, of large polygonal cells ; antheridia in tufts on both 

 sides of the frond ; tetraspores tripartite, in swollen spots on the frond ; 

 cystocarps sessile on the frond, flask-shaped, spores in dichotomously 

 branching fdaments arising from a basal idacenta. 



A genus comprising a single species, which is found from Cape Cod to Norfolk, sep- 

 arated from Iklesneria because the tetraspores are formed in incrassated sjiots on the 

 frond. The genus is too near Delesseria, of which it should perhaps form a subgenus. 



G. A:nERiCANA, Ilarv., Ner. Am. IJor., Fart 11, Fl. 21 b. (Bclcmeria 

 Americana^ Ag. — AgJaiophyllum Americanum^ Mont. — Cryptnpleura 

 Americana, Kiitz.) PL XIII, Figs. 2-4. 



Exs. — Alg. Am. Bor., Farlow, Anderson &: Eaton, Xo. G4. 



Fronds di(ecious, four inches to a foot and a half long, one to four 

 inches wide, lanceolate, tapering at the extremities, occasionally bifid 

 or i)roliferous, margin smooth or wavy; antheridia in small spots on 

 both sides of the frond ; tetraspores scattered over the frond in thickened 

 spots; cvstocarjis scattered, sessile, llask-shaped. 



