348 



FILICALES 



[CH. 



is selected as the best known and most widely-spread representa- 

 tive of Jurassic Schizaeaceae. 



Klukia exilis (Phillips)^. Fig. 259. 



The generic name Klukia was proposed by Eaciborski^ for a 

 species originally described by Phillips^ from the Inferior Oolite 

 of the Yorkshire coast as Pecopteris exilis. Bunbury's* discovery 

 (supplemented by additional evidence obtained by Raciborski) 

 of well-preserved sporangia justified the substitution of a 

 distinctive designation for the provisional term Pecopteris. 



Fig. 259. Klukia exilis (Phillips) 

 nat. size.) 



(Figs. 1—3, 



fig. 4, x3]; fig. 5, 



The species may be defined as follows: — 



Frond tripinnate, of the Cladophlehis type ; pinnae linear, lanceolate, 

 attached to the rachis at a wide angle. Ultimate segments short and 

 linear, entire or, in the lower part of a frond, crenulate, 5 mm. long or 

 occasionally longer. Sporangia 0-5 mm. in length, borne singly on the lower 

 surface of the lamina in a row on each side of the midrib. 



A re-examination^ of the specimen described by Bunbury 

 confirmed his account of the structure of the sporangia. The 

 pinna shown in fig. 259 is characterised by unusually small 

 fertile pinnules some of which bear 10 sporangia in two rows; 

 the annulus includes about 14 cells. Fertile specimens of this 

 and similar forms are figured by Raciborski® from Jurassic rocks 

 of Poland, and good examples of the English species maybe seen 



' For synonymy, see Seward (00) p. 130. " Baciborski (91). 



3 Phillips (29) A. p. 148. •» Bunbury (51) A. ^ Seward (94^) A. 



« Baciborski (94) A. 



