OTOZAHITES. 59 



Otozamites we know very little indeed as to its exact botanical 

 position, and for the present, at least, it will probably be better 

 not to bind ourselves to any of these subdivisions of the genus. 

 We may adopt a definition of Otozamites very similar to that 

 previously quoted from Bornemann, but which gives a more definite 

 expression to the variable character of the numerous forms and 

 fronds included in Braun's genus : 



Frond pinnate ; pinnae attached to the upper surface of the 

 rachis by a portion of the auriculate base, base more or less 

 distinctly auriculate, the upper lobe often more prominent than 

 the lower ; segments may be approximate, imbricate, or distinct. 

 Veins numerous and branched, radiating from the point of 

 attachment and cut off obliquely by the margin of the pinna ; in 

 the longer and narrower form of pinna the veins are practically 

 parallel to the edges of the segment ; pinnae vary from long, 

 narrow, and linear-lanceolate, with acute tips, to broadly oval 

 or almost orbicular in form, with bluntly rounded apices. 



Solms-Laubach, 1 after speaking of the flabelliform venation of 

 Otozamites, goes on to say that in some forms of this genus the 

 veins of the pinnae conform much less distinctly to that type than 

 in others. If we examine the narrower and longer forms of 

 Otozamites pinna?, the veins become more or less parallel to the 

 segment margins soon after leaving the auriculate basal portion. 

 In the longer segments of Otozamites gramineus and other species 

 this is the case, so that the flabelliform character of the venation 

 cannot by any means be relied upon as a constant and easily 

 recognized characteristic of the genus. It is often a difficult 

 matter to decide whether the pinnae bases are actually auriculate ; 

 in dealing with some fronds we find it almost impossible to 

 draw a well-marked line between Otozamites, Ctenopliyllum, and 

 Ptilopkyllum, etc. 



1 Fossil Botany, p. 89. 



