110 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



Stigmariopsis is not the root and Stigmaria the rhizome of the 

 same plant. Stigmaria is the rhizome of several genera of 

 arborescent hj^copods, including Sigillaria, while Stigmariopsis, 

 as far as one can judge at present, seems to be restricted to 

 certain Sigillarice. 



Stigmaria and Stigmariopsis are of equal position morpho- 

 logically and physiologically. They represent the same structure 

 and perform the same functions in the economy of the plants to 

 which they respectively belong. If, therefore, Stigmaria is 

 a rhizome, such must also Stigmariopsis be. Even the 

 little know T n of the structure of Stigmariopsis as described 

 by Solms-Laubach seems to me to make it impossible to regard 

 Stigmaria and Stigmariopsis as different portions of one 

 organism. 



In 1889, through the kindness of Grand 'Eury, Solms-Laubach 

 was enabled to examine in situ at St. fitienne a stem of Sigillaria 

 with the rhizomes attached, to which Grand 'Eury had given the 

 name of Stigmariopsis. The results of these investigations he 

 has published in his valuable paper, " Uber Stigmariopsis Grand 

 'Eury." This contains the first concise account of Stigmariopsis 

 with which I am acquainted, and the first to give any definite 

 characters which warrant our regarding it as a distinct genus, in 

 so far as one can apply the word genus to fossils which we know 

 are only the subterranean portion of an individual whose trunk 

 possesses another name. 



The trunk examined by Solms-Laubach divided into four arms 

 at the base in a similar manner to that which occurs in 

 Stigmaria. Owing to unfavourable preservation it was impos- 

 sible to further trace the four primary divisions. 



From the under-surface of one of these four arms, and close to 

 the base of the stem, spring two downward-directed thick conical 

 growths, which are evidently the " tap-roots " described by 

 Richard Brown as occurring on his example from the Island of 

 Cape Breton. 1 The surface of the rhizomes, as well as that of the 

 "tap-roots," is marked with Stigmarian scars, and the bark 

 between them is ornamented with flexuous lines forming an 

 irregular net-like reticulation. 



1 Quart, Journ. Geol. Soc, Vol. V., p, 354; 



