DESCRIPTION OF TUE SPECIES. 117 



AnGIOI'TERIDIUM DENTATIIM, S[). IIOV. 

 Plat.' XXX, Figs. (■>, 7. 



Frond pinnate ; Iciif-snbstance thin ; pinnules oblong-ovate, abruptly 

 narrowed at their tips, margins finely serrate, sometimes with double teeth; 

 midnerves strong- towards their bases and attenuate towards their summits, 

 ami near the apex splitting- up into branches; lateral nerves going off at a 

 very obli<iue angle and curving- out to meet the margin, simidy forked or 

 several times forking, slender but distinct. 



Localit\' : Fredericksburg; rare. 



This plant in the general shape of the pinnules and the nervation is 

 much like the Neuropterids of the Carboniferous era, and is peculiar in 

 the fine toothing of the margin. 1 place it provisionally in the genus 

 Anf/ioptf'iidiiini, but possibly this and A. onitiini should be made a new genus. 

 This plant seems to be a type between ThmiifcJdta and Aiu/iopteyuUitm. 



ASPLENIOPTERIS, gen. nov. 



Frond bipinnute or tripiuuatitiil; pinnules linear-lanceolate, or oblong, 

 acute to obtuse, lobed or toothed, sori proijortionally very large, elongate 

 to narrowly elliptical, in a row on each side of the midrib, one in each lobe 

 or tooth, inserted on thick supports or segments, which re|)resent the trans- 

 formed segments or lobes, placed on the anterior margin of these, and run- 

 ning down nearly their entire length. Type, AspJeitioptcrin piiniatijidd. 



This curious type of fern differs in some respects from all described 

 fossils. The most noteworthy feature is the contraction of the lobes or 

 teeth of the pinnules into thick leathery supports which bear the long nar- 

 row sori on their anterior margins, the general shape and position of the 

 sori resembling those features in Asplenium. Aspleniopteris phniaiijida may 

 be taken as the type, that being prett)- fully represented in the parts found. 

 The genus may be com[)ared with Dlcksonla davipcs, Heer,^ but, unlike 

 that plant, the sori are hnig, narrow, and not borne always on the summit 

 of the modified lobes The genus seems to be a composite type, uniting 

 the features of Pteris, Asplciiiuiu, and Osmunda, resembling the latter in 



' Flor. Fobs. Arc, vol. 4, pt. 2, PI. II, Fig. 7. 



