X] CALAMOSTACHYS. 361 



borne by vegetative shoots of the type of Calamites, Gala- 

 modadus or Annularia. 



1. Calamostachys^ (including Paracalamostachys and 

 Stachannularia). 



Cones long and narrow, consisting of a central axis bearing 

 alternate whorls of sterile and fertile appendages, the latter 

 having the form of sporangiophores attached at right angles 

 to the axis midway between the sterile verticils, and bearing 

 four sporangia on the inner face of a peltate distal expansion. 



Galamostachys Binneyana Schimp., C. Ludivigi Carr., C. 

 Casheana Will., may be referred to as examples of this type of 

 cone ; also some of the strobili described by different authors as 

 species of Volkmannia^, Brukmannia^, &c. 



Although one cannot make out the detailed structure of a 

 Calamite cone in the absence of internal structure, it is often 

 possible to recognise the essential features in specimens pre- 

 served in ironstone nodules, such as those from Coalbrook Dale 

 in Shropshire, or by carefully examining the carbonised im- 

 pressions on shale under a simple microscope. 



Weiss applies the term Paracalamostachys^ to cones of the 

 Galamostachys form, but in which the manner of attachment 

 cannot be made out. Such a cone as that of fig. 93 should 

 probably be referred to this sub- type of Galamostachys in the 

 absence of definite evidence as to the position of the sporangia. 



Another term Stachannularia, originally used by Weiss as 

 a genus ^ was afterwards^ applied to cones of the same general 

 type as Galamostachys, in which the sporangiophores have 

 the form of thorn-like structures bearing on their upper side 

 a lamellar expansion. There is however some doubt as to the 

 correct interpretation of the features associated with cones 

 included in Stachannularia; for an account of such forms 



1 Weiss (84), p. 161. Solms-Laubaoh, loc. cit. p. 826. 



- E.g. Volkmannia Ludwigi Carr., also Volhnannia elongata Presl. [Solras 

 (91), p. 332 and Weiss (76), p. 108]. 



=' E.g. lirukmannia Grand'Euryi Ren. [Renault (70)]. 



^ Weiss (84), p. 190. '^ Weiss (76), p. 1. 



« Weiss (84), p. 161. 



