1-40 BRITISH SEA-WEEDS. \J>Ielanosj)ermea . 



whitish fibres. The colour is an olivaceous-grcen. I do 

 not think that it is rare in the west of Scotland, but as it is 

 rather minute it does not attract notice. The first time I 

 observed it was on a shell dredged near the island of Greater 

 Cumbrae. I did not then know it ; but on sending it to 

 Professor Harvey, he told me that it was a rare native, then 

 going by the name of Pacliua joarvtila. During the months 

 of January and Tebruary 1849, I often observed it in a 

 young state on the roots of Halidrys siliqiiosa and Lmni- 

 7iaria digifata, but more frequently on the former, on the 

 solid disc of the base. In the summer of 1850, I have re- 

 peatedly dredged it ofP the Cumbrae Islands and off Arran. 

 It was generally on Venenipis decussately like a dark epi- 

 dermis, and not unfrequently the lobes were imbricated. 

 It has been dredged in Lamlash Bay by Professor and 

 Mrs. Balfour. No fructification has yet been observed in 

 Britain ; but it has been found on Swedish specimens, and 

 described by Areschoug. The substance is membranous, 

 somewhat transparent, and highly reticulated; the cells 

 quadrangular ; colour olivaceous-green. In drying, it does 

 not adhere to paper, and becomes a little darker. 



