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 preserved in ironstone nodules, such as those from Coalbrook Dale in Shropshire, or by carefully examining the carbonised impressions on shale under a simple microscope. Weiss applies the term _Paracalamostachys_[727] to cones of the _Calamostachys_ 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 _Calamostachys_ in the absence of definite evidence as to the position of the sporangia. Another term _Stachannularia_, originally used by Weiss as a genus[728], was afterwards[729] applied to cones of the same general type as _Calamostachys_, 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 reference must be made to the writings of Weiss, Renault[730], Solms-Laubach[731] and others[732]. _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. _Palaeostachya[733]._ 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 attachment 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 _Palaeostachya_ includes several species previously described under the genus _Volkmannia_[734]. Strobili of this generic type are known in organic association with Annularian branches, as well as with _Calamocladus_ and _Calamites_. 3. _Macrostachya._