V.—On the Fructification of some Ferns from the Carboniferous Formation

Abstract

In a Review of Dr Stur's Zur Morphologie und Systematik der Culmund Carbonfarne, I pointed out that he appears to have included two types of fern fructifications in his genus Calymmatotheca.The first type includes those forms originally placed in Calymmatotheca and consists of a number of exannulate sporangia arranged around a common point of attachment; the second type, which was first described in Zur. Morph., u. Syst. d. Culm- u. Carbonfarne, is there represented by C. Avoldensis and C. Frenzli. The fruit of these two species is apparently surrounded by an involucre or indusium, and it is only with this part of the fructification that we are at present acquainted. I also further indicated that in Calymmatotheca, as I proposed to restrict the genus, the fruiting portions of the frond are entirely deprived of foliage pinnules, whereas in the other type (C. Avoldensis and C. Frenzli) only a very slight modification takes place in the fertile portion of the fronds—the sporangia being borne on the ordinary foliage pinnules.