CERAMIUM 155 
pinnae usually originate a little above the middle of the cell 
from which they spring. The older of the ultimate ramuli are 
mostly spine-tipped, but those in the younger growing parts are 
usually rounded-obtuse or merely acute. There is a rudimentary 
development of a “dorsal” and a “ventral” series of branches, and 
in the place of one of these rudimentary branches there is occa- 
sionally a single basal cell crested or fringed with several short 
branchlets, suggesting, more or less, the involucrate *'conceptacle "' 
figured by Montagne (fig. 4d) as occurring on a tetrasporic plant, 
though in our material more equidistant from the bases of the 
opposite branches. Our specimens are tetrasporic or apparently 
sterile. The tetraspores are paired, with the planes of the final 
divisions usually at right angles to each other. 
CERAMIUM Ag. p.p. typ. Syn. Alg. Scand. xxvi. 1817. Harv. 
Man. Brit. Alg. 98. 1841. J. Ag. Anal. Alg. Cont. 2: 3-48. 
I894. Not Ceramion Adans. Fam. Pl. 2: 13. 1763. 
Not Ceramium Wigg. Prim. Fl. Holsat. 91. 1780. 
Not Ceramium Roth, Cat. Bot. 1: 146. 1797. 
?Apona Adans.* Fam. Pl. 2: 2, 519. 1763. 
?Episperma Raf. Prec. Somiol. 48. 1814. 
Boryna Grateloup; Bory, Dict. Class. Hist. Nat. 2: 412. 1822. 
Dictiderma Bonnem. Jour. Phys. 94: 185. 1822. (Not seen.) 
Hormoceras Kütz. Linnaea 15: 730, 732. 1842.1 
Gongroceras Kütz. loc. cit. 730, 735. 
* Under Аропа, Adanson in his index (p. 519) cites ‘‘Conferva nodosa Dill", 
which fact has been interpreted by Kuntze (Rev. Gen. Pl. 32: 394. 1898) as dx 
naming of a species which may serve to typify the genus. This species, with the aid 
of a hint from Le Jolis, he pone to be эсин ашчу кина: аз Соте = 
phanum. Dillenius, however 
from the reference “ Сопѓегуа nodosa Dill.” Айй! | оп iuge 2 cites «ойе A ропа 
the nine figures оп Dillenius’s plate 7, of which figures Le Jolis considers the first two 
to represent probably Ceramiaceae, the others five species of Batrachospermum and 
two species of Lemanea. To these species collectively Dillenius POETE the ordinal 
name “ Сопѓегуае nodosae” and this is probably what Adanson meant Бу“ Conferva 
nodosa Dill.” Тһе individual species as recognized by Dillenius А (ће poly- 
nomials Conferva marina nodosa өйлек Conferva marina nodosa, Conferva fontana 
osa, Conferva fluviatilis nodosa 
f This paper was published in Ф ЗА Heft of the volume for 1841: Kiitzing, 
in his Sp. Alg., appears to be consistent in citing 1842 as the date of this paper and 
that is probably the true date of publication. 
