332 



CALAMARIEAE. 



the middle of the interval between two leaf-whorls. Further researches will 

 perhaps succeed in removing these d.oubts. Nearly allied to Calamostachys 

 tuberculata is C. calathifera l , but in this species only the normal sporoph'ylls 

 with two or four sporangia have at present been observed. 



Palaeostachya, Weiss, differs from Calamostachys in having the whorls 

 of the sporophylls inserted immediately above the sterile whorls, it may be 

 almost said in the axils of their leaves, so that they project from them at a 

 more or less acute and not at a right angle. Only one form of this type is 



known in the petrified state, the rest are all 

 impressions. The silicified specimen in ques- 

 tion comes from Autun, and is named by 

 Renault Volkmannia gracilis 2 . He would 

 have done much better if he had given it a 

 new name, considering the difference in age 

 of the beds of Autun and Radnitz, in the 

 latter of which Sternberg's original Volk- 

 mannia was found ; and also because Sternberg 

 unites branches and cones which it is possible 

 do not belong to one another, while the rough- 

 ness of his figures precludes the possibility 

 of any certain identification. Renault's 3 draw- 

 ings show a hollow axis, and the well-known 

 lacunae answering to the initial bundles 

 reappear in its peripheral tissue. 



. The sterile whorls are separated by inter- 

 nodes of some length, and consist of as many 

 as twenty lanceolate free leaves, which are at 

 first straight and spreading, but afterwards 

 unified. 3 . Piece of "the longitudinal bend geniculately upwards, while the elongated 



tion ofa spike cf P. gracilis. Ken., from J r 



apical portions overlap one another like the 

 tiles of a roof. At the bend they show on the dorsal side a round or 

 ridge-like emergence projecting downwards. The sporangiophores are 

 inserted immediately above these sterile whorls and are axillary ; their 

 solid stalk expands into a large covering plate, from the inner side of 

 which are suspended four sporangia (Fig. 46, 3). 



The most important of the species known to us in good and clear 

 impressions is Palaeostachya elongata, Presl 4 , from the coal-producing 

 mountain country of Bohemia (Fig. 46, i and 2). The original specimen 

 in the Museum at Prague shows a much divided branch-system, composed 

 of members with the striation of Calamitae and bearing numerous elongate- 



Fic. 46. Palaeostachya. i. Habit of P. 

 elongata from Radnitz in Bohemia, a. 

 Small piece of a_similar spike more highly 

 in. i' 

 sec 

 Autun. From Zittel's Text-book. 



1 Weiss (6), t. 3, f. u, and Sterzel (3), t. 28, ff. 2-4. * Sternberg, Graf von (1), Parts 5-8, 



t. 15, ff. 1-3. 3 Renault (5), t. 2, and (2), vol. ii, tt. 18, 19. * Weiss (6), p. 108 ; t. 15. 



