444 



THE CARBONIFEROUS SYSTEM. 



grew in wet or inundated ground. They had ribbed and jointed stems 

 like the Calamites^ but with a stout internal woody cylinder, hi which 

 respect they resembled miniature Calamodendra. From the joints pro- 

 ceeded whorls of leaves, or of branchlets, bearing leaves which diflfered 

 from those of Calamites in their having a distinct middle rib or vein. 

 The fructification consisted of long slender cones or spikes, having 

 whorls of scales among the spore cases. Some authors speak of 

 Asterophyllites as only branches and leaves of Calamites ; but though 

 at first sight the resemblance is great, a close inspection shows that 

 the leaves of Asterophi/llites have a true midrib, which is wanting in 

 Calamites. Five species of Astei^ophyllites have been found in Nova 

 Scotia and New Brunswick (Fig. 165, A). 



4. Annularia. — It is questionable whether these plants should be 

 separated from Asterophyllites. The distinction is that they produce 

 branches in pairs, and that their whorls of leaves are one-sided, and 

 usually broader than those of Asterophyllites, and united into a ring 

 at their insertion on the stem. One little species is very common in 

 Nova Scotia, and a larger one hitherto included in Asterophyllites is 

 also abundant (Fig. 165, B). 



Fig. 165. — Asterophyllites, etc. 



A, Asterophyllites trinerne. (A') Leaf enlarged. 



B, Annularia splienophylloides. (B^) Leaf enlarged. 



C, Sphenophylluinerosum. (C) Leaflet enlarged. (C^j Scalarifomi vessel. 



D, Pinnularia ramosissima. 



5. Sphenophyllum. — This is one of the prettiest plants of the coal ; 

 its little whorls of wedge-shaped leaves, often scattered thickly over 



