536 THE DEVONIATS! PERIOD. 



In my specimen the pith is only half an inch in diameter, and only 

 a small portion of the wood is attached to it ; but Mr Matthew has a 

 specimen of a trunk ten inches in diameter, with the pith one inch in 

 thickness, and another 11^ inches in diameter, with the pith 2^ inches. 

 Both had the appearance of decayed trunks, so that their original size 

 may have been considerably greater. 



Mr Matthew states in reference to the mode of occuiTcnce of this 

 interesting species, that the wood is always in the state of anthracite 

 or graphite, or mineralized by iron pyrites, calc spar or silica. The 

 pith is usually calcified, but in pyritized trunks it often appears as a 

 sandstone cast with the external wrinkles of Sternbergia. The pith 

 is often eccentric, and specimens occur with two or three centres ; but 

 these either consist of several trunks in juxtaposition, or are branching 

 stems. The annual layers vary from one-eighth to one-thirtieth of an 

 inch in thickness, and adjoining layers sometimes vary from one- tenth 

 to one-twentieth of an inch. 



The trunks of this species appear to have had a strong tendency to 

 split in decay along the medullary rays, and in consequence the cross 

 section often presents a radiating structure of alternating black lines 

 representing the wedges of wood, and white rays of calc spar. The 

 heart wood seems to have had its cell walls much thickened, and in 

 consequence to have been more durable than that nearer the surface. 

 They appear to have been drift trees, and to have been much worn and 

 abraded before they were embedded in sediment. 



(Sigillarioi.) 



Sigillaria palpcbra, Dn. Ribs narrow, about a quarter of an inch 

 in width. Leaf-scars transversely acuminate, small. My only speci- 

 men is a small fragment, showing three or four ribs, and with only 

 a few of the scars preserved. The most perfect leaf-scars are shaped 

 much like a half-closed eye ; but the specimen is only a cast, and very 

 imperfect. Locality, St John. 



Stigmaria ficoides (variety), Brongniart. Large roots of Stigmaria, 

 in some instances with rootlets attached, occur, though rarely, in the 

 sandstone or arenaceous shale near St John — only two or three speci- 

 mens having been found. They are not distinguishable from some 

 varieties of the Stigmaria ficoides of the Coal measures. 



[Calamites.) 



Calamites transitionis^ Goeppert. " Canad. Nat.," vol. vi. p. 168 

 (Fig. 186). This species, so characteristic, according to Goeppert, of 

 the Upper Devonian and Lower Carboniferous series in Europe, is abun- 



