— 979 — 
away; whether the basal cell like that of A. mediterranea lives 
longer and is able to develop a new plant I am unable t, ascertain; 
but it seems most probable. 
This small Acetabularia seems to me to be very closely related 
to Acet. Farlowii and Acet. Suhrii. Acetabularia Farlowii, of which 
species I have had specimens for comparison from the Bermudas 
collected by M. A. Howe, seems however to be distinguished com- 
monly from A. Caliculus by having the apices of the rays in the 
disc more or less broadly rounded, and in that the Corona superior 
only has two hair-scars and also that the stalk has no or in any 
case only feeble and few spindleshaped swellings on the upper- 
most part and finally that the disc according to Howe is flattened. 
But I may point out that the specimens in one of my gatherings 
(Nr. 1617) from Long Point in some regards bare a close resem- 
blance to Acetabularia Farlowii, especially by having the apices of 
the rays most often broadly rounded and by seldom showing any 
indication of emargination (Fig. 7). As the figure B shows, the Corona 
superior almost had the same form as 
in my other specimens of A. Caliculus 
and had 2—3 hair-scars; the form of 
the disc was basin-shaped. Yet this col- 
lection showed a peculiarity, namely, 
that two of the specimens had two 
discs one over the other thus resem- 
bling Acet. crenulata, but even quite 
young plants had the rays rounded or 
feebly undulated in the margin and not 
at all apiculate as in A. crenulata, from 
which the plants were very different. 
That however specimens are found, of 
which it may be difficult to decide the  Fig.7. Acetabularia Caliculus 
species, is seen by M. Howe’s remark inal st a ie. ene 
(1. e. 1905, p. 577): “The zones occupied 15:1, fig. B about 60:1. 
by the two species (A. Farlowii and 
A. crenulata) occasionally, however, overlapped; the individuals 
intermingling in this common region were, as a rule, easily refer- 
red at sight to the one species or other, though once in a while 
an individual was met with whose affinities seemed at first a little 
dubious”. 
These specimens also greatly resemble Acetabularia caraibica 
