112 DICTYOTACE^.— StilophorA. iv. 



occupying the whole superficies. The dentation of the margin is of the same 

 nature as that of D. ciliata, but the teeth are very much closer and more irregular 

 in forui than in that species. 



VI. STILOPHORA. /. Ag. 



Boot a small, naked dis\ Frond cylindrical, branched, solid, or imperfectly 

 tubular ; composed of two strata of cells, the inner stratum of many rows of 

 colourless cells, of which those nearest the centre become ruptured in age, leaving 

 a cavity traversing the frond ; the outer stratum o one or two rows of minute, 

 coloured cells. Fructification, convex, wart-like sori, scattered over he branches, 

 composed of obovate spores^ nestling among moniliform, simple, densely packed 

 paranemata. 



The frond is described by Agardh as being at first tubular, but gradually 

 becoming solid with advanc'ng age. The contrary of this structure has always 

 appeared to me to be the case, the older parts being more empty than the 

 younger. 



1. Stilophoea rhizodes, J. Ag. ; frond subsolid, much and irregularly branched, 

 subdichotomous ; the apices scarcely attenuate, acute ; ramuli scattered, forked ; 

 sori densely covering the branches and ramuli. J. Ag. Sp. Alg. vol. 1, p. 85. 

 Harv. Phyc. Brit. t. 70. Spermatochnus rhizodes, Kiltz. Sp. Alg. p. 549. (Tab. 

 IX. B.). 



Hab. Near low-water mark, on other Algte in tide pools. Rare. Newhaven, 

 Dr. Durkee. Greenport, Long Island, W. H. H. Oyster Bay, N. Y. Mr. Walters. 

 (v. V.) 



Frond, in the American specimens, from four to five inches long, as thick as hog's 

 bristle, much branched, irregularly dichotomous, with rounded axils. Branches 

 flexuous, variously divided, furnished with a few lateral ramuli . hich are either 

 simple or forked above their middle. The apices are acute, but not much tapered. 

 The whole frond, in fertile specimens, is densely covered with i he prominent, wart- 

 like fructification ; each wart composed of a great many moniliform vertical fila- 

 ments, packed together. Among these the obovate spores are found lying, being 

 attached to the bases of the filaments. The colour is a greenish olive ; and the 

 substance cartilaginous and elastic when fresh, ut soon becoii ing oft and gelatin- 

 ous, and in drying the branches shrink considerabl}- and adhere strongly to paper. 



