58 OTOZAMITES. 



Schimper, in the first volume of his Trait, pal. veg, 1 adopts 

 the genus Otopteris, L. and H., but afterwards (vol. ii.) 2 accepts 

 Braun's generic name Otozamites ; he institutes a sub-genus Rhombo- 

 zamites for Otozamites Beanii and other species, and makes use 

 of one of Pomel's terms, Cyclozamitts, for Otozamites Bunhiryanus 

 and other forms. This subdivision seems quite unnecessary, and 

 tends rather to confusion than to useful classification. Saporta 3 

 retains Otozamites Bucklandi (Brong.) as the type of the genus, 

 but in his diagnosis mention is made of certain features which 

 set rather narrow limits to the generic characters ; the basal 

 callosity of the pinna? and the auriculate upper angle of the base, 

 are features which do not always appear in fronds which must 

 be referred on general grounds to the genus Otozamites. It is 

 true we frequently find that the upper lobe of the pinna base 

 is more decidedly auriculate than the lower, but this is not 

 universal. Saporta's figures of some of the species of Otozamites 

 show this quite clearly ; e.g., 0. Reglei, Sap., 4 0. Brongniarti, 

 Schimp., 5 etc. In describing the characteristics of the various 

 examples of the genus, Saporta points out the numerous varia- 

 tions from the normal type. In discussing the geological history 

 of the genus, this author refers to the absence of Otozamites from 

 Wealden and jSTeocomian strata ; since these words were written 

 several examples of Wealden forms have been discovered, and 

 the material acquired in recent years shows that the small plant 

 figured by Dunker as Cyclopteris Klipsteinii 6 is most probably a 

 species of Otozamites. The groups into which Saporta divides 

 this genus have been adopted by Schimper in Zittel's Handbuch? 

 The recognition of certain typical species as representatives of 

 different forms of a genus may in some cases be a convenient 

 aid to classification, but there is always the danger of unduly 

 emphasizing slight and unimportant differences for the sake of 

 such purely arbitrary grouping. In the case of a genus such as 



1 p. 483. 



2 p. 167. 



3 p. 45. 



* PL cix. 

 6 PI. ciii. 



6 (A. 2), Wealdenbildung, pi. ix. figs. 6 and 7. 



7 p. 221. 



