JoHNSON AND Hensman—A List of Irish Corallinacee. 27 
*M. Lejolisii, Rosan. 
Roundstone; Bear Island, Bantry Bay. 
This species is more or less distinguishable, to the naked eye 
or by the pocket lens, from I. membranacea, Lamx., which has 
larger conceptacles, more sharply marked off from the thallus. 
Microscopically MM. Lejolisti is distinguished by its hair-beset 
conceptacular pore. : 
MM. pustulata, Lamx. 
This species occurs all round the coast, especially on Phyllo- 
phora rubens, Grev. 
*M. macrocarpa, Rosan. 
Bear Island. : 
This species is easily mistaken for IW. pustulata, being distin- 
guished from it by having bisporous tetrasporangia, not tetrasporous 
ones, as in W. pustulata. 
*M. Laminarie, Cru. 
West of Ireland ; Dungarvan. 
This species is common on stalks of Laminaria, in Dungarvan 
Bay, forming thick, brittle, pink incrustations on the stalk, and 
must add largely to the manurial value of such Laminarias. 
*M. Coralline, Crn. 
This species has been collected nearly all round the Irish 
coast (not between Howth and Raven Point, the least examined 
stretch of coast for marine alge generally). It forms thick, lumpy 
expansions on Corallina officinalis, with conceptacles not much 
projecting. 
*M. confinis, Crn. 
Frenchport, county Mayo. 
Forms small, slightly thickened, hard swellings on C. officinalis, 
and on limpet shells; has vertically elongated thallus-cells and 
bisporous tetrasporangia. 
LITHOTHAMNION, Phil. 
Sub-Gen. HurirpoTHamnion, Fosl. 
Section I.—Innatee, Fosl. 
*Tithothamnion fruticulosum (Kiitz.), Fosl. 
Roundstone, M‘Calla; Great Man’s Bay. 
