V. SPH.EROCOCCOIDE.E. 95 



Of this plant I have as yet seen only small specimens, insufficient to enable me 

 to give as full a description as I could wish. The primary frond is four or five 

 inches or more in length, often a quarter to half an inch broad, linear, membra- 

 nous, traversed by a strong midrib, which gives off at acute angles alternate 

 branches, one running through each primary lobe, and giving off similar branchlets 

 to the succeeding lobes. Tlie lamina throughout is linear, extending at each side 

 of the midrib like a wing, of variable breadth in different specimens, and closely 

 penninerved with microscopic, articulated, obliquely ascending opposite veinlets, 

 eacli of which runs out into a marginal tooth or lacinula. These marginal denticu- 

 lations are sometimes minute, sometimes pi-olonged into linear, acute, ciliieform 

 processes. Tetraspores in linear-sori, extending at each side along the midrib, near 

 the apex of the smaller lacinise. Axils acute. Colour a purple-rose-red. Substance 

 delicately membranaceous. 



4. Delesseria alata, Lamour. ; frond irregularly dichotomous or alternately de- 

 compound, costate ; branches linear, quite entire at the margin ; the lamina (some- 

 times very narrow) penninerved with opposite, oblique veinlets ; sori either at the 

 apices of the segments or in proper leaflets. J. Ag. Sp. Alg. 2, p. 683. Harv. 

 Phyc. Brit. t. 247. Hypoi/lossiun alatum, Kiitz. Sp. Alg. p. 877- Delesseria angus- 

 tissima, Griff. — Harv. Phyc. Brit. t. 83. J. Ag. Sp. Alg. 2, p. 686. (an extreme 

 form, nearly destitute of membrane.) 



Hab. Boston Harbour, 3Irs. Mudge, Dr. Durkee, &c. (v. v.) 



Frond distichous, two to four inches high or more, much branched, linear, from 

 half a line to half an inch broad, alternately decompound, in a manner between 

 dichotomous and pinnate ; branches having a cartilaginous midrib winged at each 

 side with a narrow or broadish membrane, which is occasionally obsolete. My 

 American specimens are not in fruit. Colour a bright purple-lake. Substance 

 membranaceous. In drying, it does not adhere strongly to paper. 



I am not aware of this species being found south of Cape Cod. The specimens 

 from Boston are of small size and very narrow, many of them as narrow as D. 

 angustissima, Griff., but in all that I have seen there is an evident wing to the 

 midrib. 



5. Delesseria serrata, Post, and Rupr. ; " stipes winged, compressed, much 

 branched ; branches winged, alternately pinnatifid and bipinnatifid ; segments 

 linear, costate, serrated at the margin and incised or pinnated in the upper part ; 

 sori punctiform, aggregated at each side of the rib along the whole length of the 

 segments. Post, and Pupr. Illust. p. 15. J. Ag. Sp. Alg. 2, p. 696. Hypoglossum 

 serratum, Kiitz. Sp. Alg. j>. 876. 



Hab. Parasitical on the stipes of Ptilota asplenioides, at Unalaschka, Postels and 

 Ruprecht. 



