CARBONIFEROUS PERIOD. 337 



found to have the characteristics of the Stigmaria; and these roots 

 often lie in great numbers in the under-clays of the coal beds. In 

 Nova Scotia and England, Sigillaria stumps have been observed 

 with Stigmaria roots. Lesquereux, however, maintains that the 

 Stigmarise are sometimes, at least, stems, and not roots. 



Fig. 570 is the Stigmaria ficoides, a species which is said to have a range 

 through the whole Coal measures, — which may be true if more than one species 

 be not confounded under the name. Sigillaria minuta occurs in the Catskill 

 epoch of the Devonian ; other species, in the Upper Coal measures. 



4. Catamites. — These jointed rush-like plants sometimes grew to a 

 height of twenty feet or more, and were associates of the Sigillaria^ 

 in the marshes, being common throughout the Coal measures. 



Fig. 583 represents C. cannseformis, one of the Lower Coal-measure species. 

 C. Cistii Brngt. and C. nodosus Schlotheim are other American Lower-Coal 

 species, as well as foreign ; C. Pachyderma is found only in the Millstone grit 

 below (Lesquereux). 



5. Conifers. — Coniferous trunks and stumps are common through 

 the Coal measures, and occur also far down in the Devonian. But 

 it is remarkable that their leaves have been seldom found. The 

 Sternbergiaz, which are abundant in Ohio, and at Pictou, Nova Scotia, 

 have been shown by Dawson and Williamson to be, in some cases, 

 casts of the pithy or open cellular interior of some Conifers. They 

 are thick, cylindrical stems, much wrinkled circularly, consisting 

 of the same arenaceous material as the rock in which they occur 

 buried. Occasionally they have a carbonaceous exterior, which is 

 the woody part of the former tree. In Nova Scotia specimens, as 

 well as those of England, a coniferous structure has been observed 

 in the coaly exterior, and also a very open cellular structure, 

 through the sandstone interior. One of the Devonian species from 

 Pictou is not distinguishable in its microscopic structure from the 

 Pinites (Dadoxylon) Brandlingi of Witham. 



Most of the known Carboniferous species are related [Dadoxylon 

 included) to the genus Araucarites. The American species thus far 

 made out belong to the genus Dadoxylon (Dawson). 



Fruits of Conifers and other plants. — Besides the remains of trunks 

 of Conifers, various fruits are found in the Carboniferous beds. 

 Those which have been referred to the genus Trigonocarpum, accord- 

 ing to Hooker, are the fruit of Conifers, and resemble most that 

 of the Chinese genus Salisburia of the Yew family [Taxinex). Accord- 

 ing to Dawson, they are the fruit of Sigillarise. 



Figs. 571 to 574 (by Newberry) represent nuts or fruits from the Lower Coal ; 

 fig. 571 a, b, c, d, is Trigonocarpum tricuspidatum Newberry; a, the nut; b, the 



