MARINE ALG.^ OF NEW ENGLAND. 125 



branchlets, numerous, tripartite or polysporic; favellse terminal on 

 lateral branches, usually composed of several distinct lobes, furnished 

 -svitli an involucre by the growth of a few incurved accessory branches 

 below. 



On wharves and Fuel. 



New York, Harvey; New Haven, Professor Eaton; Newport ; New 

 Bedford ; Wood's Holl ; Europe. 



Apparently rather a common species, especially on wharves and Fuci at low-water 

 mark. The species is easily recognized, when in fruit, by the polysporic tetraspores 

 and by the favella?, which are terminal, not lateral, as in the rest of our species, and 

 have -a sort of involucre formed by the growth of accessory ramuli from the cells just 

 below the favella?. When sterile the species may be recognized by the regular, 

 broadly pinnate tips, at the end of nearly naked branches. We have found both poly- 

 spores and favellrc on American specimens ; and in spite of the fact that our plants are 

 always more slender than European forms of the species, there can be almost no doubt 

 that we have the true C. Borreri. Whether all the sterile forms referred by Ameri- 

 can botanists to C. Borreri are correctly determined is doubtful. Some perhaps belong 

 rather to C. roseum. The present species is placed by Bornet in the genus Corynospora, 

 because of the terminal and involcurate favellas and polysporic tetraspores. As 

 writers differ about the limits of Corynospora, we have kept the species in Callitham- 

 nion, although in some respects it differs from the rest of the genus, and the young 

 stages of the cystocarps remind one strongly of Spermothamnion. The fruit is, how- 

 ever, a true favella. The number of spores in the polyspores in American specimens 

 rarely exceeds 8 or 10, whereas Nsegeli puts the number as high as 20-28 in European 

 specimens. As usually found in early summer, the species is small and delicate, but 

 later it becomes coarse. Specimens collected as late as possible in the autumn are to 

 be desired, and the number of spores in a polyspore should be ascertained more defi- 

 nitely. In Contributiones ad Algologiam et Fungologiam, p. 44, PI. 23, Fig. 1, 

 Eeinsch describes and figures a Callithamnion Labradorense, which is said to have poly- 

 spores — whether a polysporic condition of C. floccosum or not can hardly be deter- 

 mined from the description. 



Subgenus EUCALLITHAMNION. 



Fronds erect, cortications generally present ; antheridia in tufts, either 

 on the nodes or internodes of the branchlets ; tetraspores tripartite ; fa- 

 vella^ usually binate, lateral. 



Sect. I. Pennat^:. 



Growth monopodia!, fronds distichously pinnate, pinnw alternate, corti- 

 coMons rudimentary or wanting. 



G. roseum, (Roth), Harvey. (G. roseum, Phyc. Brit., PI. 230.— Phle- 

 bothamnion roseum, Kiitz.) 



Fronds capillary, two to four inches high, filaments diffusely branched 

 below, main branches slightly corticated, secondary branches long, 

 flexuous, distichously pinnate, pinnse crowded at the ends of the branches, 

 long, spreading or slightly incurved ; antheridia in tufts on the nodes 

 of the branchlets; tetraspores tripartite, sessile on the branchlets; fa- 

 velhc binate on the upper branches. 



