TEMPSKYA. 149 
usually included under that name are only incomplete pieces of 
fern stems, any attempted diagnosis would be of little value. 
Solms-Laubach! speaks of certain forms of Rachiopteris occurring 
in the ‘‘ Zempskya condition”; and this probably means that they 
are imbedded in a felted mass of adventitious roots. As will be 
shown in the sequel, certain species previously referred to this 
genus have been proved by the examination of more perfect 
material to be referable to other and more precisely defined 
genera. It will be well for the present to retain Corda’s term, 
if we regard it as implying a particular manner of preservation 
rather than any well-defined generic characters. Used in this 
provisional sense, Zempskya includes such specimens of tree-ferns 
as consist in the main of felted masses of adventitious roots, 
with occasional petioles associated with them, and which are 
without any distinct vascular cylinder. 
Velenovsky has made some important additions to our know- 
ledge of these Zempskya forms, which will be referred to under 
T. Schimperi, Cord. 
I am indebted to Prof. Stenzel,? of Breslau, for certain im- 
portant suggestions as to the nature of the genus Zempskya. He 
points out that this term is occasionally used in the case of 
specimens which consist simply of roots without any trace of 
stems; he mentions the receipt of such a ‘‘ Zempskya”’ from the 
late Dr. Stur, and compares the structure of the roots to that 
characteristic of Protopteris punctata or P. microrhiza. This form 
of Zempskya, as Stenzel adds, does not conform to the original 
description by Corda, in which reference is made to petioles asso- 
ciated with numerous roots. 
In referring to Corda’s opinion that Zempskya probably repre- 
sents a portion of a tree-fern stem above the actual stem apex,* 
Stenzel justly points to the great masses of roots in different 
species of this genus as a fatal objection to such a view. Stenzel 
adds that Corda’s specimens must have been pieces from the lower 
part of a stem; but, judging by the great thickness of the root- 
mass on one side of the stem of 7. pulchra and T. Schimperi as 
figured by Corda,‘ there must have been a considerable length of 
1 Fossil Botany, p. 159. 
2 Letter, Dec. 1893. 
3 Flor. Vorwelt, p. 81. 
4 Ibid. pl. lviii. fig. 1; pl. lix. fig. 1. 
