XI. 

 SIGILLARIEAE. 



IT has been observed above in describing Lepidodendron, that the 

 Sigillariae rank next to that genus from the similarity of the surface-char- 

 acter of their stems, and indeed come so near it, that certain species have 

 repeatedly given occasion to confusion between the two groups. Unfor- 

 tunately we are not so well acquainted with the development and structure 

 of all the separate parts of the plants in Sigillarieae as in Lepidodendreae ; 

 fragments of stems are extremely abundant in the form of impressions and 

 casts, but as regards the anatomical structure, the fructifications, and even 

 the foliage leaves, we have to be content with the information to be derived 

 from a few scanty remains. The duration of Sigillarieae in the series of 

 formations resembles that of Lepidodendreae, but is still more limited. 

 Sigillarieae disappear with Lepidodendreae in the Rothliegende, having 

 been found in the lower members of that formation near Autun, near Olten- 

 dorf in Bohemia 1 , and near Schmalkald ; but they do not make their 

 appearance before the beginning of the Coal-measures, and are still 

 extremely rare in its lowermost deposits, in the Millstone Grit for example. 

 They appear in great abundance, and as the dominant form of vegetation 

 only in the middle deposits of this period, as in the Schatzlar and Saar- 

 briicken beds. Stur 2 has put together a number of species from the base 

 of the whole formation. Some older remains supposed to belong to the 

 group are mentioned by Goppert 3 , but they are more than doubtful. The 

 same may be said not only of the form known as Sigillaria Vanuxemii, 

 Gopp 4 , from the Chemung (Devonian) beds of Oswego in New York, but 

 also and more particularly of his S. Hausmanniana 5 , which was found by 

 Hausmann in the beginning of the century between Idre and Sarna in Nor- 

 way in supposed Lower Devonian strata. Later authors have rightly deter- 

 mined that this specimen is merely a ripple-mark. In the other direction 

 from beds that are more recent than the Rothliegende I only know of 

 one fragment described and figured from the Upper Bunter Sandstone of 



1 Goppert (3). 2 Stur (5), p. 292. 3 Goppert (19), p. 543. * Varmxem (1), 



p. 184, f. 51. 5 Goppert (19), t. 35, f. i. 



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