372 CALAMITES. [CH. 



several different ' forms ' of stems, which differ from Sternberg's 

 fossil in such points as the number of nodes between the 

 branch -whorls and the number of branches in each whorl. The 

 result of this system of nomenclature is the separation of portions 

 of one specific type under different form-names. It must be 

 clearly recognised that accurate specific diagnoses are practically 

 impossible when we have to deal with fragments of plants, 

 some of which are mere pith-casts, while others show the surface 

 features. The specimen represented in fig. 99 agrees with a 

 stem described by Ettingshausen^ in 1855 as Galamites Gopperti, 

 and as a matter of convenience a member of the Calamitina 

 group showing such characters may be referred to as Calamites 

 (Calamitina) Gopperti (Ett.). The following list, which includes 

 a few synonyms of this form, may suffice to illustrate the 

 difficulties connected with accurate systematic determinations. 



Calamites (Calamitina) Gopperti (Ett.). Fig. 99. 



1855. Calamites Gopperti, Ettingshausen ^. 



1869. Calamites {Calamophyllites) Gopperti, Grand'Eury^. 



1874. Cydocladia major, FeistmanteP. 



1874. Calamites verticillatus, Williamson^. 



1876. Calamitina Gopperti, Weiss ^. 



1884. Calamites {Calamitina) varians ahhreviatus, Weiss'". 



1884. Calamites {Calamitina) varians inconstans, Weiss ^. 



1887. Calamites Sachsei, Stur^. 



1888. Calamophyllites Gopperti, Zeiller^*^. 



This species is characterised by the smooth bark, which may 

 be traversed by a few irregular longitudinal fissures ; most of 

 the nodes bear a series of small leaf- scars, and at fairly regular- 

 intervals a node is immediately succeeded by a circle of 

 contiguous branch-scars, 8 — -12 in a whorl. The pith-cast of 

 this type of stem has short ribbed internodes separated by 



1 Ettingshausen (55), PL i. fig. 4. - Ettingshausen, lac. cit. 



» Grand'Eury (69), p. 709. ^ Feistmantel (75), PI. i. fig. 8. 



5 Williamson (74), PI. vii. fig. 45. « Weiss (76), PI. xvii. figs. 1 and 2. 



7 Weiss (84), PL xvi a. figs. 10 and 11. ^ jjjid, Pl. xxv. fig. 2. 



9 Stur (87), PL II. etc. ^^^ Zeiller (88), p. 363, PI. lvii. fig. 1. 



