(40) 



larger cells," rather smaller towards the surface, roundish angular. Sub- 

 stance cartilaginous, but soon becoming flaccid, closely adhering to the 

 paper in drying. Colour, when fresh, greenish olive ; when dry, greenish 

 brown. 



This fine and delicate species is of very limited geographical distri- 

 bution, being rather scarce in Britain, and chiefly found in the southern 

 portions of the country. On the coast of France it is also found, but 

 still more rarely, and has not been met with out of Europe. Unlike 

 some of our other rarer species, it seems to prefer the south-east rather 

 than the south-west of these islands, and on the east coast has been 

 found as far north as the Frith of Forth, but we have not seen or heard 

 of its occurrence in Forfarshire. 



It seems " to prefer old shells to rocks for its habitat, and rather deep 

 sheltered pools or quiet bays, near low-water mark." 



We have met with specimens having receptacles on the main stem, 

 and these were of much larger size than those of the branches ; and in 

 most of our specimens the pedicels of the full-grown receptacles are 

 longer than the receptacles. 



EXPLANATION OF PLATE CXLV. 



Fig. 1. — SjMwchmis pediinculatus, uatural size. 

 2. — Receptacles from base of stem. 

 3. — Receptacles from summit of stem. 

 4. — Apical filaments. 

 5. — Sporiferous filaments from receptacle. All magnified. 



