378 CALAMITES. [CH. 



recently been made by Sterzel^, who admits the impossibility 

 of separating the specific forms by means of the data at our 

 disposal, but for purposes of geological correlation he prefers 

 to express slight differences by means of definite ' forms ' or 

 varieties. The more comprehensive use of the specific name 

 criidatus as adopted by Zeiller in his Flore de Valenciennes ^ is, 

 I believe, the better method to adopt. The specimen shown in 

 fig. 102 affords a good example of a typical Calamites cruciatus, 

 it was found in the Middle Coal-Measures near Barnsley, 

 Yorkshire. 



Calamites (Eiicalamites) cruciatus (Sternb.). Fig. 102. 



1826. Calamites cruciatus, Sternberg^. 



1828. Calamites cruciatus, Brongniart*. 



1831. Calamites alternans, Germar and Kaulfuss*^. 



1837. Calamites approximatus, Lindley and Hutton*'. 



1877. Calamodendrofloyos cruciatus, Grand'Eury''. 



1878. Calamodendron cruciatum, Zeiller s. 



1884. Calamites {Eucalamites) cruciatus ter7iarius, AVeiss^. 

 1884. „ „ „ quaternarius, Weiss ^. 



1884. „ „ „ genarius, Weiss ^. 



1884. „ „ multiramis, Weiss ^. 



1888. Calamites {Calamodendron) cruciatus, Zeiller i^. 



This species occurs in the Upper, Middle and Lower Coal- 

 Measures". The casts of the cruciatus type have been found 

 associated with wood possessing the structural features of the 

 sub-genus Calamodendron^^, but our knowledge of the structure 

 of the stem, and of the fertile branches of C. cruciatus is very 

 imperfect. A restoration of Calamites {Eucalamites) cruciatus 

 is given by Stur^^ in his classic work on the Calamites, but 

 he does not make quite clear the supposed connection with 



1 Sterzel (93), p. 66. 2 ZejUer, loc. cit. p. 353. 



3 Sternberg (25), PI. xlix. fig. 5. * Brongniart (28^), p. 128, PI. xix. 



5 Germar and Kaulfuss (31), p. 221, PI. xlv. fig. 1. 



6 Lindley and Button (31), PI. ccxvi. ^ Grand'Eury (77), p. 293. 

 8 Zeiller (80), PI. clxxiv. (expl. plates) fig. 3. 



8 Weiss (84), pp. 112, 113, 114. 10 Zeiller (88), p. 353. 



11 Kidston (94), p. 249. ^^ Grand'Eury (90), p. 216 (expl. plates). 



13 Stur (87), p. 68. 



