380 CALAMITES. [CH. 



authors for separating pith-casts of Calamodendron and Ar- 

 thropitys stems do not appear to be satisfactory ; we want some 

 term to apply to all Calamitean casts irrespective of the anato- 

 mical features of the stems, or of the precise nature of the foliage- 

 branches. As used in the present chapter, Catamites stands 

 for plants differing in certain features but possessing common 

 structural characters, which must be defined in a broad sense so 

 as to include types which may be worthy of generic rank, but 

 which for convenience sake are included in a comprehensive 

 generic name. The attempts to associate certain forms of foliage 

 with Arth^opitys on the one hand and with Calamodendron 

 on the other, cannot be said to be entirely satisfactory ; we still 

 lack data for a trustworthy diagnosis of distinct Calamarian 

 genera which shall include external characters as well as 

 histological features. If we restricted the genus Catamites to 

 stems with an Arthropitys structure and an Asterophyllitean 

 foliage, we should be driven into unavoidable error. Within 

 certain limits it is possible to distinguish generically or even 

 specifically between petrified branches, and we already possess 

 material enough for fairly complete diagnoses founded on 

 internal structure ; but it is not possible to make a parallel 

 classification for pith-casts and foliage-shoots. For this reason, 

 and especially bearing in mind the importance of naming 

 isolated foliage-shoots and stem-casts for geological purposes, I 

 believe it is better to admit the artificially wide application of 

 the name Catamites, and to express more accurate knowledge, 

 where possible, by the addition of a subgeneric term. In 

 dealing with distinctions exhibited by Calamitean stems it may 

 be advisable to make use of specific names, but we must keep 

 before us the probability of the pith-cast and petrified stem- 

 fragment of the same plant receiving different specific names. 

 If the structural type is designated by a special sub-genus, this 

 will tend to minimise the anomaly of using more than one 

 binominal designation for what may be the same individual. 



The following summary may serve to bring together the 

 different generic and subgeneric terms which have been used 

 in the foregoing account of Catamites. 



