XXXVlJ CYCADELLA 417 



shows clear indications of concentric rings, probably the expression 

 of seasonal changes during the production of secondary conducting 

 tissue by a single cambium. Similar concentric rings have been 

 described in the stems of the recent Cycad Dioon spinulosum 1 . 

 Fig. 539 represents an ovulate strobilus referred to this species 

 by Wieland. 



'Cycadeoidea pumila Fliche and Zeiller. 



This French Portlandian species 2 affords a good example of 

 a very small bulbiform trunk, 3-5 4 by 2-5 3 cm., superficially 

 resembling a Pine-cone : the leaf-bases are, however, less uniform 

 in size and shape than Abietineous cone-scales; there are also 

 indications of interpetiolar ramenta and a small lateral, presumably 

 fertile, branch. A stem of similar form is described by Saporta 3 

 from Corallian beds in France as Bulbopodium micromerum, and 

 Cycadeoidea nana Ward 4 from Dakota is another example of 

 a small Zamia-like Mesozoic stem. A small tuberous stem, 

 8 x ? 5 cm., was described by Lindley and Hutton from Lyme 

 Regis as Cycadeoidea pygmaea 5 ', no flowers are shown in the 

 drawing, but occasional irregularities in the arrangement of the 

 leaf-bases may be due to the presence of lateral fertile shoots. 



Cycadella. Ward. 



This generic name was instituted by Lester Ward 6 for some 

 petrified stems from Jurassic beds in Wyoming of relatively small 

 size, bulbous or more or less 'spherical, and characterised by the 

 presence of a thick layer (5 15 mm.) of dense ramental tissue. 

 The unusually vigorous development of the ramental scales is 

 an interesting feature, though it is perhaps questionable whether 

 it is worthy of generic recognition. The flowers of Cycadella, 

 though less than those of most Cycadeoidea stems, are of the same 

 type. In a later account of the genus Ward 7 describes a few 

 additional species and in Cycadella ramentosa he notes the preserva- 

 tion of young fronds. The fronds are small and bear a few pinnae : 



1 Chamberlain (09). 2 Fliche and Zeiller (04) p. 789, PI. xix. 



3 Saporta (75) A. p. 262, PI. 118. 



4 Ward (99) B. p. 639, Pis. CLVI., CLVII. 



5 Lindley and Hutton (35) A. PL 143. (I have not seen the actual specimen 

 A. C. S.) 



6 Ward (OO 2 ), Pis. xiv. xxi. 1 Ibid (05) B p 198j pls XLVI _ 



s. m 27 



