( 150) 



First observed in the Orkney Islands by the Rev. J. H. Pollexfen, and 

 pubhshed as new in the Annals of Natural History for 1844, under the 

 name of C. Polleocfenii, by Dr. Harvey, who afterwards found it to be 

 identical with the C. floccosiim of Agardh and of Flora Danica. 



It is perhaps better distinguished by its straggling habit and simple 

 ramvili tlian by any other character. The ramuli are extremely short 

 and spine-like, rarely with more than six or seven articulations, and are 

 almost invariably simple, pretty regularly opposite, but frequently want- 

 ing, especially in the lower parts of the stem and branches, seldom in 

 the upper. 



It seems rather a northern species ; we have not heard of its occur- 

 rence in England, and on the Scottish shores it is by no means frequent, 

 occurring in single plants, and at wide intervals. We have met with it 

 several times on the Forfarshire coast, but it is not common, and very 

 rarely in fruit. Its favom-ite habitat seems to be the large stones in 

 intratidal pools which are always under w^ater, on which it sometimes 

 forms considerable tufts. 



The articulations are generally somewhat inflated, but wdien branched, 

 contracted at their insertion. We are just favoured with a communica- 

 tion from our good friend Mr. T. Bell of Peterhead, regarding this species, 

 in which he says : " It is common at Peterhead. I have found it with 

 favellse at the tips of the branches, surrounded by a tuft of fine branchlets. 

 It is very common this year, and was last, with favellas — the year before 

 much rarer." Along with this communication we have received several 

 fine specimens confirmatory of the above remarks, so that the sentence 

 in our " descrijjtion " — " Favellee appear not to have been seen in this 

 country" — must be cancelled. 



CALLITHAMNKiN FLOCCOStJM. 



EXPLANATION OF DISSECTIONS. 



Fig. 1.— Branchlet. 



2. — Portion of same witli tetraspores. 

 3. — A tetraspore. All ma^uified. 



