OF ARKANSAS. 309 



These are enumerated in the table with a mention of the place where 

 the j have been found. 



1. Hymenophyllites flexicaulis, Sp. nov. (PI. 1, fig. 1 and la). Frond 

 much branched, four to five times pinnately divided. Divisions alternate. 

 Primary and secondary rachis broad, flattened on the margins, inflated in 

 the middle, somewhat regularly bent at each ramification. Branchlets 

 exactly flexuose, bending in a zigzag way from the point of attachment of 

 each leaflet, which thus appear as a continuation of the rachis. Leaflets 

 oval-lanceolate in outline, small, scarcely an eighth of an inch long, pal- 

 mately divided in three or four or pinnately in five lobes. Divisions 

 linear-lanceolate obtuse, marked by a single medial nerve, decurrent in the 

 branchlet. Fig. 1 a is an enlarged leaf of this fern which, though some- 

 what related to Sphenopteris flexuosa, Gutb., an European species, differs 

 from it by well-marked characters. It abounds in the shales of Mr. Male's 

 coal-bank on the Middle Fork of "White River, Washington County. 



2. Sphenophyllum bifurcatum, Sp. nov. (Tab. 1, ~Q.g. 2 and 2 a). Stem 

 thick, branching, inflated at the articulations, deeply furrowed, smooth. 

 Leaves in whorls of nine or ten cuneiform, or flabellate leaflets, narrowed 

 near the base, dilated above, regularly divided two times. Primary divi- 

 sions deeper ; secondary ones lanceolate acute, diverging, each marked by 

 a strong medial nerve ascending to the point. This species is distantly 

 related to Sphenophyllum diehotomum, Germ. & Kaulf, and to Sphenophyllum 

 oblong if olium, Germ. Though fragments of the different parts of the plant 

 were found the form of the leaves does not show any variation. Fig. 2 a 

 shows a whorl of leaves, enlarged two times. The leaflets appear united 

 at the base but it may be an appearance of the stone. Sphenophyllum 

 trifoliatum Lsqx., of the Pennsylvania State Geological Report, p. 853, 

 tab. 1, fig. 7, may be referred to this species. Found in the shales of 

 Male's coal and of James' Fork of Poteau. 



3. Alethopteris Owenii, Sp. nov. (PL 2, fig. 1 and 1 a). Frond large, bi- or 

 tripinnate. Eachis or stem broad, thick, nodose, striate. Secondary divi- 

 sions or pinnae perpendicular to the stem ; pinnules ovate-lanceolate or 

 lanceolate in some parts of the frond, generally obtuse, sometimes pointed, 

 with undulate margins united near the base and perpendicular on the 

 rachis. Medial nerve well marked, but generally thin, sometimes deep ; 

 nervules forking twice. This fine species, dedicated to Dr. D. Dale Owen, 

 the celebrated geologist, director of the survey of Arkansas, abounds at 

 Male's and also at Lee-creek coal, but was found only in broken pieces. 

 It differs from Alethopteris Coxiana, Lsqx., its nearest relative, by narrower, 

 less undulate or more entire leaflets, apparently thick and coriaceous, and 

 by a general appearance total y different. 



4. Staphyloptosis stellata, Sp. nov. (PI. 2, lag. 2, 2 a and 2 b). These re- 

 mains apparently belong to the sporanges of a fern borne on a distinct 



