590 ON TRIPLOSPORITE, 



ing to Lejndostrohts, be really distinct from that genus ; 

 and although there are still several points of difference 

 remaining, namely, the form of the strobilus in Tri]^los2)orite, 

 confirmed by a second specimen presently to be noticed, 

 and in Lejndostrohis the more limited insertion of spo- 

 rangimn, and the very remarkable difference in the form of 

 the unripe spores, hardly reconcilable with a similar origin 

 to that described in Triplosporite, I am upon the whole in- 

 clined to reduce my fossil to Lejpidodrohus until we are, from 

 still more complete specimens of that genus, better able to 

 judge of the value of these differences. The name Tru 

 plosjoorites, however, is already adopted, and a correct generic 

 character given, in the second edition of Professor Unger's 

 ' Genera et Species Plantarum Fossilium,' p. 270, pubhshed 

 in 1850, who at the date of his preface in 1849 was -not 

 aware of Dr. Hooker's essay on Lejndostrohiis, the character 

 of which he has adopted entirely from M. Brongniart's 

 account. 



In October 1849 M. Brongniart showed me a fossil so 

 closely resembling the Triplosporite^ both in form and size, 

 that at first sight I concluded it was the lower half of the 

 same strobilus. On examination, however, it proved to be 

 of somewhat greater diameter. It was nearly in the same 

 mineral state, except that the crystallizations consequent on 

 loss of substance were rather less numerous ; it diflPered also 

 in the central part of the axis being still more complete ; in 

 the bracteee being more di-stant and of a slightly different 

 474] form : but the spores in composition, form, and apparently 

 in size were identical. This specimen had then very recently 

 been received from the Strasburg Museum, but nothing was 

 known of its origin or history. 



May 5, 1851. 



D. H. HILL LIBRARY 

 Horth Carolina State College 



