180 CRYPTONEMIACE^. v 



cimens which have grown again after having been injured. Barren specimens are 

 perfectly smooth ; nucleiferous ones are densely verrucose with the very abundant, 

 closely set, depressed, hemispheroidal nuclei. Specimens containing tetraspores are 

 smooth, but closely dotted over the surface with minute, deep coloured sori. Colour 

 a dull brown red, sometimes purplish, fading into greenish. Substance rather thick, 

 coriaceous, not very glossy. 



My specimens from Douglas (can they be Agardh's J. minor ?) are smaller than 

 some of those from Dr. Coulter, but appear to be specifically the same. 



3. iRiDiEA cordata, J. Ag. ; "frond cordate-ovate, sub -acuminate, smooth, abruptly 

 passing into a very short channelled stipes." J. Ag. Sp. Alg. 2, p. 254. Fucus cor- 

 datus, Turn. Hist. t. 116. 



Hab. Banks Island, on the N. W. Coast, Menzies. 



Fronds said to be about a foot long and six inches wide, oblong-cordate, sub- 

 acute, flattish or undulate at the margin. 



4. Irid^a pimicea, Post, and Rupr. ; " lamina membranaceous, orbicular in out- 

 line, fixed by the margin or lower surface, plaited, here and there perforated, entire 

 or eroso-dentate, of a deep crimson-lake colour." Post, and Eupr. Illustr. p. 18. 



Hab. Isle of Sitcha, Postels and Ruprecht. 



5. InroiEA pinnata, Post, and Rupr. ; '' lamina membranaceous, thickened, linear, 

 regularly bi-tripinnate, purple ; pinnae and pinnules linear, divaricate, narrowed at 

 the base, very entire or ciliato-pinnate at the margin." Post, and Rupr. Illust. p. 

 18. 



Hab. Norfolk Bay, N. W. Coast, Postels and Ruprecht. 



vSaid to resemble CalUblepharis jubata in habit, but to have the structure of 

 Iridcea. May it not rather be a species of Gigartina, possibly our G. mollis? 



XL CHONDRUS. Stack. 



Frond carnoso-cartilaginous, flat, dichotomous, fastigiate, composed of two strata 

 of cells ; the medullary stratum of cylindrical, articulated filaments anastomosing 



