FLORA OF THE GALAPAGOS ISLANDS. 91 
praecipue in parte ‘inferiore phylliculis vestita quae basem versus deorsum 
ad instar radicorum prolongantur. Sori oosporiferi minuti irregulariter 
supra frondem sparsi.— ALBEMARLE Isx.: Turtle Pt., March, 1899, 
Snodgrass & Heller. 
In all the specimens there are leaflets on both surfaces of the fronds 
except near the tips. ‘They arise from the cortical cells, and have no 
connection with the fructification which is found on the frond _ itself, 
Near the base the leaflets grow downward, become somewhat thicker 
and twisted and bear on their lower surface the proper rhizoids so that 
the fronds are attached by what is generally called a fibrous base. In 
spite of the leaflets which would lead one to refer this alga to the genus 
Glossophora, it seems to me to be less closely related to G. Kunthii, J. Ag. 
of Peru, the type of the genus, than to Dictyota crenulata, J. Ag. of the 
Pacific Coast of Mexico. As originally described from Mexico that 
species has no leaflets and the base is described as stuposo. In 188 
Grunow described a variety from the Canary Islands with leaflets, but its 
relation to that species is uncertain. The Galapagos species differs so 
much from D. crenulata as originally described, and from the var. cana- 
riensis that it must be kept distinct. If material hereafter collected 
should show that the two species are really forms of a single species, a 
new description will be needed. The following notes on the microscopic 
structure of the Galapagos alga will be of interest. 
In the upper part the frond is about 100 u thick, becoming 200 w thick 
below. Above, there is a single medullary layer of large cells 70 » X 
70» X 168, and a single layer of colored cortical cells 144 X 144 in 
section. Below, the cortical cells become rather deeper, 22 » X 14 in 
section, and the medullary cells thicker-walled and comparatively nar- 
rower, 112 4 X 564 in section, and between the medullary and cortical 
cells is a single layer of flattened colorless cells, 28 ~ xX 28 X 90 p. 
The tangential walls of the medullary cells are pitted to an extent seldom 
seen in algae of this order. The oogonia are 80 or more in diameter 
and found in small numbers in scattered sori on the frond. The spines 
are sharper and more solid than in most of the ciliate species, 24-32 mm. 
long, the tips deeper colored than the base. 
Papina, Adams. 
P. Durvitraet, Bory, Coquille, 147, t. 21, f. 1 (1829). — ALBEMARLE 
Isx. ; Tagus Cove, and Turtle Pt., Feb. & Mar. 1899, Snodgrass & 
Heller, Cuatuam Ist: north, Ang 191, Baur as Zonaria lobata. 
Further distrib. W. Ind., west coast of Am. 
