i68 HISTORICAL PALEONTOLOGY. 



uncompressed stems growing in an erect position, and some- 

 times attaining a length of twenty feet or more. Externally, the 

 stems are longitudinally ribbed, with transverse joints at regular 

 intervals, these joints giving origin to a whorl of branchlets, 

 which may or may not give origin to similar whorls of smaller 

 branchlets still. The stems, further, were hollow, with trans- 

 verse partitions at the joints, and having neither true wood nor 

 bark, but only a thin external fibrous shell. There can be little 

 doubt but that the Catamites are properly regarded as colossal 

 representatives of the little Horse-tails (Equisetacece} of the 

 present day. They agree with these not only in the general 

 details of their organization, but also in the fact that the fruit 

 was a species of cone, bearing " spore-cases " under scales. 

 According to Principal Dawson, the Calamites "grew in dense 



Fig. lOS.Odontopteris Schlothelmii. Carboniferous, Europe and North America. 



brakes on the sandy and muddy flats, subject to inundation, 

 or perhaps even in water; and they had the power of budding 

 out from the base of the stem, so as to form clumps of plants, 

 and also of securing their foothold by numerous cord-like roots 

 proceeding from various heights on the lower part of the 

 stem. " 



The Lepidodendroids, represented mainly by the genus 

 Lepidodendron itself (fig. no), were large tree-like plants, 

 which attain their maximum in the Carboniferous period, but 



