220 OIOZAMITES. 



one and the same plant are, indeed, greater than between some of 

 the so-called species of this type of frond. It is wiser to admit 

 that we cannot hope to accurately separate species hy such fine 

 distinctions as have been discovered in the form of the pinnse of 

 fronds from difEerent localities. A slight difference in geological 

 age is often responsible for the undue importance attached to 

 almost imperceptible distinctions, which are raised to the rank of 

 specific characters. 



In the list of synonyms I have included such forms as agree most 

 nearly with Otozamites ohtusus, L. & H. ; it is not meant to imply 

 that the several ' species ' are identical, but that they are all 

 characterized by the possession of fronds conforming in the main 

 to one type ; such small differences as may be recognized are not 

 considered sufficient to warrant their use as specific characters. It 

 may be convenient to retain some, at least, of the specific names as 

 varietal or ' form ' designations. The Inferior Oolite fronds which 

 Phillips spoke of as Oto%amUes ohtusus ^ may be spoken of as 

 Otozamites ohtusus (L. & H.), var. ooliticus, in order to draw 

 a distinction between the Inferior Oolite fronds and the closely 

 allied, but not absolutely identical, type of Liassic age. 



There are some very good examples of this type of Otozamites 

 m the York Museum, one of which, labelled by Bean Otopteris 

 £rapMoa, has a length of 17 cm. The pinnae have pointed apices, 

 and the upper edge of the base is distinctly auriculate. 



39,201. PI. I. Fig. 1. 



This frond, of which a few pinnae are represented in the 

 'drawing, measures 40 cm. in length, and is one of the most 

 beautiful examples of a fossil Cycadean leaf in the Museum 

 Collection. The portion figured is a little above the middle of 

 the whole frond. The pinnse vary very slightly in size (about 

 6 cm. long and 1 cm. broad) throughout the length of the frond ; 

 they are obliquely attached to the upper face of the rachis, and 

 the upper edge of the base is prominently eared. The apices 

 arc obtusely pointed ; the upper edge of the lower pinnse is 

 somewhat more falcate than in those shown in Pig. 1, but the 

 more strongly curved and sharply pointed pinnse of Otosamites 



' Phillips (75), p. 222. 



