HOWE: PHYCOLOGICAL STUDIES 509 
from ‘Golden Gate, California,’ but they agree closely in habit, 
color, and structure. 
The pericentral siphons are usually ten in number but vary 
from nine to eleven. The basal internodes are 6-10 times as long 
as wide. Simple colorless monosiphonous ‘“‘leaves”’ are abundant 
at the tips. 
CENTROCERAS CLAVULATUM (Ag.) Mont. in Durieu, Fl. Algérie 1: 
140. 1846 
Ceramium clavulatum Ag. in Kunth, Syn. Pl. Aeq. 1: 2. 1822. 
La Paz, in the herbarium of the New York Botanical Garden, 
ex herb. C. L. Anderson, collector unknown. 
The fragmentary specimen is from a stouter and more spiny 
plant than the original Ceramium clavulatum Ag., which was 
brought from Callao, Peru, by Humboldt. It also has shorter 
internodes and more forcipate apices. It suggests Kiitzing’s figures 
of his Centroceras oxyacanthum, drawn from a South African speci- 
men, though originally described from Cuban material; however, 
the spines are less conspicuous than in C. oxyacanthum and are not 
much in evidence, except at the apices. 
The type of C. clavulatum in herb. Agardh is a slender plant 
with rather strict dichotomies, the tuft standing about 3.5 cm. 
high. The filaments are 85-110u in diameter; the internodes are 
320-510u long below, becoming about 80-100 long under the 
terminal dichotomy; the apices are incurved only in the youngest 
growth stages and are scarcely forcipate in the usual sense of the 
term; no lateral innovations were noticed; the spines are few, 
small, erect or incurved, and very inconspicuous, consisting of one 
or two cells and rarely reaching a length of 4ou. Kiitzing was 
doubtless right in suspecting* that the original Ceramium clavu- 
latum belonged with his own Centroceras cryptacanthum, of which 
his var. 8. longiarticulatum came from the coast of Peru, the type 
region of Ceramium clavulatum Ag. 
Halymenia actinophysa sp. nov. 
Thallus plane, sessile (?), very thin (70—-130,), gelatinous- 
membranous, elliptic-obovate or irregularly orbicular, attaining 
a length of 30 cm. or more and width of 20 cm., occasionally and 
* Linnaea 15: 742, 743. 1841. 
