Page:Transactions NZ Institute Volume 15.djvu/328

I have not seen Lundell's description of his plant, which appears to be very rare in England. But, in the "Midland Naturalist," vol. iv., 1881, I find C. cyclicum figured by Mr. A. W. Wills, without description. Assuming, as is most probable, that this figure is accurate, the English plant differs from ours in having a deep narrow constriction, so that the segments approximate quite closely and indeed touch each other. In the New Zealand variety the wide shallow constriction is quite conspicuous, and the segments diverge from each other at once.

C. botrytis, Bory. (R. XVI.)

In my former paper I expressed doubts as to this species; but many specimens have since come under my observation and there is no doubt that the plant occurs here plentifully. It is common near Christchurch and in the Cust Valley.

C. tetraophthalmum, Kützing. (R. XVII, XXXIII.)

Var. α, the large form. S.

I have no specimens from Canterbury which I can with certainty refer to this plant, but several occur in gatherings from Hawke's Bay. I see no difference between it and the English plant.

Var. β, the small form.

The frond is small, more orbicular than in var. α, the segments being broader than long and the pearly granules are much smaller, indeed inconspicuous. I should not have considered the two as the same species, were it not that in one of Mr. Joshua's English gatherings I find a plant (apparently identical with this) which is labelled "Cos. tetraophthalmum, small form, zygospores, not botrytis, fide Nordstedt." In that gathering are some specimens in conjugation, and I have been fortunate enough to find one here also in the same condition, as shown in my figure. I may observe that Ralfs, in his description of the large form, says,—"the sporangia are large and their spines finally branched;" but in his pl. xxxiii. he figures the spines as subulate. Those of my English specimens are also subulate, but probably in both instances the zygospores are not mature.

Length in front view, 44 μ; breadth, 40 μ; diameter of zygospore, including spines, 65 μ.

Rare: from Lyttelton.

C. undulatum, Corda, var. β, var. nov. (?)

The distinctive character of this plant is its small size, the length being only 33 μ, the breadth about the same. In Ralfs' plate xv. two sizes are shown, but both are larger than our plant, and the measurement given in the same work is, length ¹⁄₄₁₆ of an inch, or about 63 μ.