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BIBLIOGRAPHY. 
Dr. Kjellman considers that it should be placed in a separate 
genus, and names it Myelophycus ccespitosum, Kjellm. He is of 
opinion that it should be placed in the family Jtncceliacece, between 
Coilodesme or Soranthera and Asperococcus. The fronds have the 
habit of Scytosiphon , but the internal structure bears so consider- 
able a resemblance to Chordciria , and the unilocular sporangia are 
so similarly placed among the paraphyses that it is easy to under- 
stand why Professor Harvey referred it to that genus. The fertile 
surface is, however, apparently not continuous, and the axis or 
central portion consists of large thin-walled cells. E. M. H. 
Pogotrichum hibernicum , Sp. Nov. By T. Johnson, D.Sc., F.L.S. 
(Scientific Proceedings of the Royal Dublin Society, Yol. 
viii., n.s., Part I., No. 1.) 
The diagnosis of this new species of Pogotrichum is thus given : 
— “ Unbranched, tufted filamentous thalli, 1 c.m long, of radially 
constructed cross-section, and intercalary growth. Basal cells of 
filaments rhizogenous, and penetrating Alaria thallus to give new 
tufts by endophytic hyphae. Filaments hairy, each one assimila- 
tive and reproductive, solid or subsolid. Chromatophores granular, 
4-20, parietal. 
** Sporangia unilocular and plurilocular in same tuft, but not in 
same filament, chiefly in upper parts of filaments, which part may 
become entirely converted into reproductive cells. Sporangia 
formed intercalarily, from individual joint-cells of thallus in uni- 
seriate filaments, or from superficial cells, or from all the cells of 
multiseriate filaments. Fate of zoospores unknown. 
“ Habitat. — On Alaria esculenta , Grev. (young plants) at 
Kilkee, co. Glare, in September. 
“ Affinities. — Very near to, if not identical with, Litosiphon 
Laminarias , Harv.” 
From an examination of authentic specimens of Harvey’s Lito- 
siphon Laminarice, preserved in the Herbarium of Trinity College, 
Dublin, Prof. Johnson came to the conclusion not only that his 
Kilkee plant is closely, perhaps too closely, related to that species, 
but also that the genera Litosiphon and Pogotrichum were one and 
the same. Prof. Reinke, when he founded the genus Pogotrichum , 
pointed out that it might eventually have to be degraded to the 
rank of a sub-genus of Litosiphon , and perhaps that would be the 
best course to adopt, since the fructification of the species of both 
genera appears to be similar. We have, through the kindness of 
Prof. Johnson, been able to examine specimens of Pogotrichum 
hibernicum with both kinds of fruit, and we are inclined to think 
that although undoubtedly closely related to L. Laminarice , it is 
specifically distinct from it. Litosiphon Laminarice is a larger plant 
tnan P. hibernicum , with proportionately smaller superficial cells, 
and a curious subarticulate appearance, when fresh, which is quite 
wanting in the latter; moreover, fertile uniseriate filaments are 
very frequently met with in the tufts of Pogotrichum hibernicum , 
