362 CALAMITES. [CH. 



reference must be made to the writings of Weiss, Renault \ 

 Solms-Laubach^ and othersl 



Calamostachys cones have been found in organic union 

 with branches bearing leaves of the Annularia type, also with 

 Calamocladus foliage, and the branches bearing such cones 

 have been found in actual connection with Calamitean stems. 

 The association of cones and vegetative stems and branches is 

 shown in tabular form on p. 363. 



2. PalaeostachyaK 



In this genus the general habit agrees with that of 

 Calamostachys, and in imperfectly preserved specimens it may 

 be impossible to discriminate between Calamostachys and 

 Palaeostachya. The latter form is characterised by the attach- 

 ment of the sporangiophores in the axil of the sterile bracts, 

 or immediately above them, as shown in figs. 97 and 98. 



Examples. Palaeostachya vera sp. nov., P. pedunculata Will, 

 afford examples of this form of strobilus. The genus Palaeo- 

 stachya includes several species previously described under the 

 genus Volkmannia^. 



Strobili of this generic type are known in organic association 

 with Annularian branches, as well as with Calamocladus and 

 Calamites. 



3. Macrostachya. 



This generic name was originally applied by Schimper^ to 

 certain forms of Calamitean stems, of the type afterwards 

 referred to the sub-genus Calamitina hy Weiss, bearing long 

 and thick cones. The name is, however, more appropriately 

 restricted to strobili, which differ from the two preceding genera 

 in their greater length (14 — 16 cm.) and in the more crowded 

 and imbricating whorls of bracts. The internodes of the 

 cones are very short, and each whorl of bracts consists of about 

 20 coherent members separated at the periphery of the disc 



1 Eenault (82), p. 139; (76). ^ Solms-Laubach (91), p. 330. 



3 Schenk (88), p. 132; (83), p. 232. ^ Weiss (84), p. 161. 



5 E.g. Volkmannia gracilis Sternb. [Eenault (76), PL ii.]. 



6 Schimper (69), p. 332. Vide also Eenault and Zeiller (88), p. 420. 



