ROOM I. 



CALAMITES. 



29 



some examples, there are remains of a stellate sheath en- 

 circling the joints, but this is altogether different from the 



Lies. 4. CALAMITES, FROM THE COAL FORMATIOK. 

 Fig. 1. Calamites radiatus. (^ not. size.) 



2. Stem with roots. (^ not. size.) 



3. Calamites approximates. (| not. size.) 



cylindrical sheath of the Equisetacese. The stems 

 attain a height of forty or fifty feet, and a diameter of 

 one to three feet. When specimens are lying in the sam 

 plane with the lines of stratification, they are generally 

 pressed flat; but when found in an erect position, they re- 

 tain their natural cylindrical form. The bark, in the state 

 of a carbonaceous crust, frequently invests the stem; but I 

 have not been able to detect any traces of internal structure. 

 The axis of the stem appears to have perished, and its place 

 is occupied by clay or sand. Yestiges of the roots are some- 

 times preserved. 1 The case comprises several species: as 

 Calamites approximatus, C. canniformis, C. nodosus, 0. deco- 

 ratus, &G. 



1 Specimens are figured in "Medals of Creation," p. 110; and seven 

 species in "Pictorial Atlas of Organic Remains," PI. XIII. XVII. 

 p. 43. 



