340 



CALLITRINEAE 



[CH. 



FIG. 761. CalUtrites cur fa. 



A. cone of five valves. 



B, C, two views of a sec- 

 tion of a f our- valved cone. 

 (British Museum, drawn 

 from specimens described 

 by Gardner; nat. size.) 



CalUtrites curta (Bowerbank). 



Bowerbank referred several pyritised cones from the London 

 Clay of the Island of Sheppey to Cupres- 

 sites and some of them he compared with 

 species of Callitris. Gardner 1 , as the result 

 of an examination' of Bowerbank's type- 

 specimens,, reduced the number of species 

 and adopted the name Callitris. The speci- 

 mens, in the British Museum, assigned to 

 CalUtrites curta are conical cones composed 

 of 4, 5, or rarely 6 thick and woody valves 

 which are sometimes unequal in size: the 

 largest has a diameter of 2 cm. Fig. 761, 

 A shows a cone of five valves and B, C, are 

 two views of a section of a cone consisting 

 of four valves. A similar type described 

 by Gardner as Callitris Ettingshauseni 2 , 

 also from Sheppey, is represented by glo- 

 bular cones 12 15 mm. in diameter and 

 composed of 6 8 scales. These two species are probably correctly 

 referred to the Callitrineae though the pyritised cones are the only 

 portions of the plant preserved in the Sheppey clay. Gardner states 

 that Ettingshausen 3 is incorrect in recording CalUtrites curta from 

 the Isle of Wight. 



CalUtrites Brongniarti (Endlicher). 



This species, first described by Brongniart 4 as Equisetum 

 brachyodon from the Paris Basin, is recorded from many European 

 localities, in some cases represented only by sterile shoots but 

 frequently also by cones and small winged seeds. Some well pre- 

 served specimens are figured by Unger 5 from the Tyrol (fig. 762, 

 A, A') under the name Thuyites callitrina characterised by regularly 

 whorled leaves, apparently four at each node, with a relatively 

 long and narrow appressed lamina and a small free apex and by 

 valvate cones. Unger 6 subsequently described good specimens as 



1 Gardner (86) p. 21, PI. ix. figs. 7, 21. 2 Ibid. PL ix. figs. 16. 



3 Ettingshausen (79) p. 392; (80) p. 231. 



4 Brongniart (22) A. p. 329, PL v. fig. 3; Endlicher (47) p. 274. 



6 Unger (47) p. 22, Pis. vi., vn. 6 Ibid. (67) p. 42, PL i. figs. 1, 2. 





