XII. 

 STIGMARIA. 



THE Stigmariae are some of the best-known and commonest of fossil 

 forms, and are constantly to be found on every refuse-heap in a coal-mine. 

 They occur sometimes as cylindrical casts of greater or less thickness beset 

 with peculiar regularly disposed scars, sometimes as impressions in which 

 long finger-like appendages with blunt terminations are attached to the 

 scars. The distribution of these remains through the series of formations 

 agrees very nearly with that of Lepidodendreae. Most abundant in the 

 Coal-measures they are still frequent in the Carboniferous Limestone, and 

 may be traced backwards into the Devonian formation. Dawson ] has 

 figured remains from St. John in New Brunswick and from Gaspe, of which 

 Stigmaria perlata 2 at least may be regarded as certainly belonging to this 

 group. They are found in the other direction as high as the Rothliegende, 

 in which, as we see, the last undoubted Sigillariae occur, at Autun for 

 example, and also according to Weiss 3 near Schmalkald in Thuringia and 

 near Zorge in the Harz. Above this point they disappear entirely. The 

 most complete collection of the older literature on Stigmaria is to be found 

 in Goppert 4 and Weiss 5 ; for the newer the reader may be referred to 

 Renault 6 and to Williamson's 7 last publication. 



The common species, which is generally distributed through the strata 

 from the Limestone below to the upper beds of 4he Carboniferous formation, 

 is Stigmaria ficoides, Brongn. ; and closely connected with it are a number 

 of other forms which will be briefly noticed presently, and which are treated 

 by most authors, by Goppert also and Schimper^, as mere varieties, though 

 some at least of them differ greatly from it in habit. The casts of Stigmaria 

 ficoides, usually merely cylindrical fragments, are not unfrequently of con- 

 siderable length. Hooker 9 mentions some that were twenty metres, 

 Goppert 10 one that was thirty metres in length. Their branching is always 

 dichotomous, and the two arms of the bifurcation pursue a parallel course 



1 Dawson (1), vol. i, t. 3. 2 Dawson (1), vol. i, t. 3, f. 32. 3 Weiss (1). * Copper 



(3), (20). 5 Weiss (1), p. 171. 6 Renault (2), vol. ii, p. 152, vol. iii, Introd. and (10). 



7 Williamson (6). 8 Schimper (1). 9 Hooker (4), p. 432. I0 Goppert (3), p. 188. 



