130 Mr. E,. Kidston on a new Species of 



to prepare a scheme in which can be brought together those 

 species that have certain points in common. 



Although the groups proposed by Weiss may be more or 

 less artificial, the necessities of the case demand some such 

 scheme in which can be arranged the data for a more perfect 

 classification. 



CaLAMAEIjE. 



Calamites, Suckow. 



Division A. — Ribs on stems alternating at the nodes or 

 joints. 



Group I. Calamitina (emend.), Weiss. 



Calamitina (emend.), Weiss, Steinkohlen-Calamarien, part ii. p. 59 

 (1884)*. 



Branch-scars occurring periodically, the nodes bearing scars 

 being separated from each other by a certain number of joints 

 which do not bear branches. In most cases there is a regular 

 increase or decrease in the length of the joints which connect 

 the branch-bearing nodes. 



Example: — Calamites varians, Sternberg. 



Group II. E u C A L A M I T E s, Weiss. 



Eucalamites, Weiss, ibid, part ii. p. 96 (1884). 



Branch-scars occurring on every joint. The joints are of 

 the same length or of irregularly different lengths. 

 Example : — Calamites ramosus^ Artis. 



Group III. Stylocalamites, Weiss. 



Stylocalamites, Wei&s, ihid. part ii. p. 119 (1884). 



Branch-scars occurring without definite order, of subordi- 

 nate importance ; often long stretches of the stem occur on 

 which the branch-scars are entirely absent. The joints are 

 of equal length or of irregularly different lengths. 



Example: — Calamites Suckowii, Brongn. 



* Part i. in ' Abliandl. z. geol. Specialkarte v. Preussen u. d. Thiirin- 

 gischen Staaten, Baud ii. Heft i. (1876) ; part ii. ibid. Band v. Heft ii. 



(1884). 



