484 
PACIFIC SCIENCE, Vol. XIX, October 1965 
FIG. 1. Viva reticulata f. delicatula f. n. A, Habit 
sketch of small portion of frond; B, transverse section 
of frond showing cell outlines. 
Frond entangled in other algae, apparently 
unattached, its segments narrow and reticulate, 
the meshes numerous and small, thus giving 
the frond a delicate appearance; frond 32-3 6 g 
thick, cells in two layers, 7 ( 1 0— 11 ) — 1 3 /x diam 
in surface view, nearly round in cross sectional 
view, loosely arranged in the gelatinous matrix. 
COLLECTION: Gilbert 9947, TYPE, Kahaluu 
Park, S of Kailua, Hawaii, May 26, 1959. 
This collection was first reported by the 
writer (1962:143) as Viva reticulata Forsskal 
(1775:187) but later study suggested it is suf- 
ficiently different to be regarded as a form of 
that species. It differs from forma reticulata in 
its much more delicate appearance resulting 
from the extremely fine meshes, in the fact that 
the frond is thinner (32-36 g, as compared 
with the usual 50-76 /x), and in that the cells 
are less closely arranged and at most only slightly 
elongated when viewed in a cross section of the 
frond. 
12. Ulva rigida C. Agardh, 1822, p. 410. 
The following collection is assigned with 
some uncertainty to this species. Only two 
fronds were found in a large mound of algae 
washed up on the beach by wind and wave 
action. One frond was a very dark green and 
both were relatively stiff and leathery, certainly 
different to the touch from other Ulva in the 
pile. The two fronds are ovate, about 11 cm 
in length with a distinct but very short petiole. 
The fronds reach 137 /x in thickness. When 
seen in a cross section of the frond the cells 
are vertically elongated, up to 4 times their 
width in length, and the gelatinous matrix be- 
tween and external to the cell layers is wide. 
COLLECTION: Gilbert 9188, in wash at 
Naska, Maui, March 23, 1959. 
13. Chaetomorpha antennina (Bory) Kiitzing, 
1849, p.379. 
This species commonly occurs where exposed 
to surf and actively moving water as in spill- 
ways. Rather large quantities of material have 
been examined with particular reference to the 
basal cell and considerable variation in basal 
cell size and degree of annulation have been 
noted. For example, in plants which appear to 
belong to the same clone (of Gilbert 9761) 
there are a few apparently mature plants with 
basal cells having no annulations, but in most 
plants the annulations are distinct and numer- 
ous. This species has been reported previously 
by several authors and only representative col- 
lections of my own are reported. 
COLLECTIONS: Gilbert 9141, Kalama Park, 
Maui, March 23, 1959; 9417, near Kahe Point, 
Oahu, April 11, 1959; 9761, base of Na Pali 
Cliffs, near Mana, Kauai, May 3, 1959; 9839, 
Onekahakaha Beach, Hilo, Hawaii, May 22, 
1959; 10079, ca. 3 miles N of Wailua, Molokai, 
June 6, 1959. 
14. Chaetomorpha paucitatis sp. n. 
Fig. 2 
Plantae non crebrae, dilute virides, 4.5-5 cm 
alt., metallicae rigidaeque, parte in inferiore laxe 
2-3 convolutae, in penicillis 2-5 plantarum 
singularum; cellulae basales 200-700 g long., 
57-130 [x lat., longioribus a crescentia rhizoide- 
orum secondariurum, quae e cellulis supra in 
cellulam basalem primariam, hapteron discoid- 
eum habentem, descendunt, orientibus; cellulae 
in filamento inferiore 150-190 /x diam, ad septa 
interdum constrictae supra maiora (ad 500 g) 
factae, et per formationem zoosporarum inflata; 
membrana cellularum striata, crassitudine vari- 
