336 CAXAMITES. [CH. 



partially expanded Calamitean foliage-shoot. The central axis, 

 6-5 cm. in length, includes about 15 intemodes, and terminates 

 in a bud covered by several small leaves. Lateral branches are 

 given off at a wide angle, and small unexpanded buds occur in 

 the axils of several of the leaves. 



As an example of the leaf-bearing branches which Grand'- 

 Eury has recently described as Calamocladus, using the genus 

 in a more restricted sense than is adopted in the present 

 chapter, reference may be made to the fragment shown in 

 fig. 68, A. The foliage-shoots of this type bore verticils of linear 

 leaves, coherent basally in the form of a cup, at the ends of 

 branches and not in a succession of whorls on each branch. 

 The association of reproductive organs, in the form of long 

 and narrow strobili, with Calamocladus is referred to in the 

 sequel. 



The specimens described by Grand'Eury are in the Ecole 

 des Mines Museum, Paris ; some of the shoots which are well 

 preserved bear a resemblance in habit of growth to the genus 

 A rchaeocalamites. 



/S. Annularia. 



In 1820 this generic name was applied by Sternberg^ to 

 some specimens of branches bearing verticils of linear leaves. 

 In 1828 Brongniart'"' thus defined the genus Annularia: — 

 " Slender stem, articulated, with opposite branches arising 

 above the leaves. Leaves verticillate, flat, frequently obtuse, 

 traversed by a single vein, fused basally and of unequal 

 length." 



In the works of earlier writers we find frequent illustrations 

 of specimens of Annularia, which are compared with Asters and 

 other recent flowering plants. Lehmann' contributed a paper 

 to the Royal Academy of Berlin in 1756, in which he referred 

 to certain fossil plants as probable examples of flowers, among 

 them being a specimen of Annularia. He refers to the oc- 

 currence of fossil ferns and other plants, and asks why we do 



1 Sternberg (20). 2 Brongniart (28), p. 155. 



' Lehmann (1756), p. 127. Vide also Volkmanns (1720), PI. xv. p. 113. 



