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REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 125
branchlets, numerous, tripartite or polysporic; favellæ terminal on lateral branches,
usually composed of several distinct lobes, furnished with an involucre by the
growth of a few incurved accessory branches below.
On wharves and Fuci.
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 favellæ, 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 favellæ. When sterile the species may be recognized by the regular,
broadly pinnate tips, at the end of nearly naked branches. We have found both polyspores and favellæ
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 American 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 [sic?] favellæ and polysporic tetraspores. As writers differ
about the limits of Corynospora, we have kept the species in Callithamnion, 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, however, a true favella. The number of spores in the polyspores in
American specimens rarely exceeds 8 or 10, whereas Nægeli 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 definitely. In Contributiones ad Algologiam
et Fungologiam, p. 44, Pl. 23, Fig. 1, Reinsch 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
determined from the description.
SUBGENUS EUCALLITHAMNION.
Fronds erect, cortications generally present; antheridia in tufts, either on the nodes
or internodes of the branchlets; tetraspores tripartite; favellæ usually binate, lateral.
Sect. I. PENNATÆ.
Growth monopodial, fronds distichously pinnate, pinnæ alternate, cortications
rudimentary or wanting.
C. ROSEUM, (Roth), Harvey. (C. roseum, Phyc. Brit., Pl. 230.—Phlebothamnion
roseum, Kütz.
Fronds capillary, two to four inches high, filaments diffusely branched below, main
branches slightly corticated, secondary branches long, flexuous, distichously
pinnate, pinnæ 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; favellæ binate on the upper branches.