BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 4, pp. 119-132, pl. 1 February 23, 1893 



A NEW TSENIOPTEROID FERN AND ITS ALLIES 



BY DAVID WHITE 



(Read before the Society August 16, 1892) 

 ( !ONTENTS 



Paste 



Introduction 119 



Diagnosis 119 



Locality 120 



Specific Resemblances. 120 



Generic Reference 121 



Suggested genetic Relations 123 



Systematic Position and Relation of the megalopterid Group 125 



Graphic Presentation of Relations 129 



Conclusions 129 



Introduction. — Among several collections of fossil plants from the Lower 

 ( !oal Measures of the Carboniferous of Henry county, Missouri, have been 

 found a number of specimens representing a remarkable and apparently 

 new species which presents a striking combination of tseniopteroid and 

 alethopteroid characters. Tins species is of peculiar interest from the 

 fact that it exhibits divisions of a type well known in certain Paleozoic 

 and Mesozoic tseniopteroid forms arranged and developed in the manner 

 familiar in the genus Alethopteris, as will be seen in the accompanying 

 figures and following description : 



Tseniopteris missouriensis, n. sp. 



Pl. I, figures 1-7. 



Diagnosis. — Fronds bipinnate(tripinnate?),the larger divisions linear- 

 lanceolate, acute, composed of pinnatifid pinnules near the base, above 

 which are simple pinnules; primary rachis broad, shining, marked by 

 somewhat irregular lines, and consisting of a thickened central portion, 

 broadly but shallowly canaliculate above, half-round below, and of 

 thinner marginal laminae ; pinnules opposite, sub-opposite or alternate, 



XVIII— Buo,. Gkol. Soc. Am., Vol. 1, 1892. (U") 



