WITHAMIA. 



173 



Specimens of Doubtful Position. 



Genus WITHAMIA, gen. nov. 



In the second volume of the Plantes Jurassiques, Saporta figures 

 two specimens under the generic name Cycadorachis, 1 C. armata* 

 Sap., from the Lower Kimmeridgian, and C. abscissa, 3 Sap., from 

 the same horizon. The former species is represented by a fairly 

 stout axis bearing four spinous recurved appendages, having the 

 appearance of rose thorns. This is not unnaturally compared 

 with the rachis of a cycadean petiole, in which, as in recent 

 species of Cycas and Dioon, the lower pinnae are reduced to 

 spiny processes. 



The genus is thus denned : 



" Rachides frondium foliolis destitutes vel etiam frondium partes 

 infers, petioli dicta?, sive nudaa sint, sive aculeis armataB, aut 

 ad basin insertionis causa paullo dilatatam squamatis e tomento 

 piloso constantibus ad utrumque latus praBditaa videantur." 



Such a provisional genus like that of Rachiopteris among ferns, 

 is a useful institution, and the species Cycadorachis abscissa may 

 well be included in it; but the discovery by Mr. Rufford of 

 several specimens very similar to Saporta's C. armata, negatives 

 the suggested relationship to a cycadean frond. 



In the Ecclesbourne (Hastings) specimens there are large leaf- 

 like structures attached to the axis in the axils of the spines, 

 and, without attempting to speak definitely as to the precise 

 nature of these two kinds of appendages, it would seem unwise 

 to retain a generic designation indicating a cycadean alliance. 

 Although it is held by some a wrong course to adopt, I propose to 

 substitute, in the case of Cycadorachis armata, Sap., and the almost 

 identical fossils from the English Wealden, a new generic name in 

 place of that instituted by Saporta. To retain Saporta's genus, with 



1 Pal. Fran^. vol. ii. p. 193. 



2 Ibid. p. 196, pi. cxvii. fig. 1. 



3 Ibid. p. 198, pi. cxiv. fig. 3. 



