SPHE-NOPTERIS. 131 



usually giving off simple or bifurcating nervules to eacli segment, 

 lobe, or tooth. 



Sphenopteris is one of the largest, and at the same time most 

 unsatisfactory, of form-genera. In it are placed fern-like fronds 

 of deeply cut or lobed habit, belonging to rocks of many different 

 ages, and presenting no evidence with regard to the fructification. 

 Consequently their true systematic position is unknown. This 

 type of frond occurs not only in the Pala3ozoic, Mesozoic, and 

 Tertiary periods, but can be matched among several genera of 

 recent ferns. 



1. Sphenopteris polymorpha, Feistmantel. 

 (Text-fig. 31.) 



1850. ? Peroptcris affinis, M'Clelland, Rep. Geol. Suit. India, p. 56, pi. xiii, 



figs. 11, 11a, 116. 

 1861. Peeopteris (?), Bunbury, Quart. Journ. Geol. Soc, vol. xvii, p. 331, 



pi. is, figs. 6-8. 

 ? Cladophlebis, Bunbury, ibid., p. 332, pi. x, fig. 1. 

 1876. Spheiioptcns polymorpha, Feistmantel, Journ. Asiat. Soc. Bengal, 



vol. xlv, pt. 2, p. 356, pi. xvi, figs. 5-7 ; pi. xvii, figs. 1-3. 

 1S80. S. polymorpha, Feistmantel, Flora Gondw. Syst., vol. iii, pts. 2, 3, 



pp. 76, 77, pis. xv a, xviA, fig. 3 ; pi. xvi a bis, figs. 1-6. 

 ? Cyathea cf. Tchihatcheffi, Feistmantel, ibid., p. 75, pi. xviA, 



figs. 1, 2, 4. 

 1882. Sphenopteris polymorpha, Feistmantel, ibid., vol. iv, pt. 1, p. 28. 

 1886. ? Cyathea cf. Tehihatchefi, Feistmantel, ibid., vol. iv, pt. 2, p. 23. 

 1893. Sphenopteris polymorpha, Oldham, Man. Geol. India, pi. opp. p. 162. 

 1902. S. polymorpha, Arber, Quart. Journ. Geol. Soc, vol. lvni, p. 12, pi. i, 



figs. 4, 5. 

 *S. polymorpha, Arber, Geol. Mag., dec. iv, vol. ix, p. 348. 



Types. M'Clelland's and Feistmantel' s in (?) Mus. Geol. Surv. 

 India, Calcutta. 



Frond tripinnate. Eachis broadly winged. Primary pinnae 

 alternate, or sub-opposite, springing from the primary axis at 

 a wide angle, greatly varied in shape, pinnate in the upper portion 

 of the frond, with slightly sinuate or lobed pinnules ; median pinnae 

 longer, also pinnate, with more deeply incised pinnules ; lower 

 pinnae distinctly bipinnate, with denticulate pinnules. Secondary 

 pinna; alternate or sub-opposite. Primary nerve of the ultimate 

 pinnae giving off bifurcating nervules to the lobes of the pinnules. 



