168 CRYPTONEMIACE.E. v. 



elongated cells, longest towards the centre, shorter toward the margin ; the cortical 

 of moniliforin, vertical, closely packed, short filaments formed of minute coloured 

 cellules. Conceptacular nucleus immersed in the frond, sub-prominent, consisting of 

 several associated nuclei or masses of minute spores. Nemathecia (?) external, sur- 

 rounding the branches, wart-like, formed of radiating, very densely packed, slender 

 filaments 



Nearly related apparently to the last genus, with which I have formerly felt dis- 

 posed to unite it. It difters, however, in the much greater density of cellular 

 structure and more rigid substance of the frond. The typical species, A. pllcata, is 

 widely dispersed, being couimon on both shores of the Atlantic, in the Pacific 

 Ocean, and extending into high southern latitudes. The other species are local, 

 and comparatively little known. 



1. Ahnfeltia plicata, Fries ; frond homy, terete, filiform, very irregularly 

 branched, entangled ; branches di-trichotomous, with lateral proliferous often se- 

 cund ramuli ; axils rounded, apices curving upwards, the terminal shoots elongate. 

 /. Ac/. Sp. Alg. 2, p. 311. Gymnogongrus jilicatus, Kiitz. Sp. Alg. p. 789. Haw. 

 Phyc. Brit, t 288. Fucus plicatus, Turn. Hist. tab. 180. E. Bot. tab. 1089- ^-fas- 

 tigiata ; frond more regularly dichotomous, the apices of equal length, Gymnogon- 

 grus fastigiatus Post, and Rupr.! Alg. Buss. p. 16. 



Hab. Boston Bay, Mr. G. B. Emerson, Dr. Asa Gray, &c. Rhode Island, Prof, 

 Bailey. New York, Ji/-. Calverley. ^. Unalaschka, Wosnessensky ! }A.aM&^, W. H. H. 

 Boston Bay, Mr. Emerson, (v. v.) 



Fronds densely tufted, often forming intricate bundles some inches in diameter 

 and 9 or 10 inches long. Stems filiform, twice as thick as hog's bristle, very irre- 

 gularly branched, more or less dichotomous, especially below ; the lesser divisions 

 often lengthened and beset with lateral alternate or secund, erecto-patent branch- 

 lets. In var. ^. the tufts are often perfectly level-topped as if clipped with a 

 shears ; the fronds regularly dichotomous with distant lower forks and approxi- 

 mate upper ones. Coheir a blackish purple. Substa7ice very rigid and wiry. It 

 does not adhere to paper in dryino-. 



I have been favoured by Dr. Ruprecht with an original specimen of his Gymno- 

 gongrus fastigiatus, but can by no means distinguish it from a fastigiate variety of 

 A. plicata which accompanies the ordinary form in Boston and Halifax Harbours. 



2. Ahnteltia gigartinoides. J. Ag. ; " frond carnoso-corneous, terete, dichotomous 

 and secundly decompound-proliferous ; the proliferous ramuli very patent, obtuse ; 

 the segments erect from the rather acute axils, the terminal ones elongate." /. 

 Ag. Sp. Alg. 2, p. 311. Gymnogongrus gigartinoides, Kiitz. Sp. Alg. p. 789- 



