172 PACHYPTERIS. 



1856. Pachyptcris lanceolata, Zigno, Flor. foss. Oolit. vol. i p. 73. 



Dichopteris lanceolata, ibid. p. 118, pi. xiv. fig. 2. 



Pachypteris ovata, ibid. p. 74. 



Dichopteris lavigata, ibid. p. 118, pi. xiv. fig. 3. 

 1869. Pachypteris ovata, Schimper, Trait, pal. veg. vol. i. p. 492. 

 1873. Scleropteris Phittipsii, Saporta, Pal. Fran9- p. 369, pi. xiv. fig. 2. 



S. lavigata, ibid. p. 370, pi. xlvi. fig. 3. 



Pachypteris lanceolata, ibid. p. 366, pi. xiv. fig. 1. 



P. ovata, ibid. p. 370, pi. xlvi. fig. 2. 



1875. Dichopteris lanceolata, Phillips, Geol. Yorks. p. 200, pi. x. fig. 6. 

 D. lavigata, ibid. p. 201, pi. x. fig. 9. 



1876. Cf. Pachypteris brevipinnata, Feistmantel, Pal. Ind. pi. iii. fig. 7 ; 



pi. iv. figs. 1-3. 



1879. Cf. Dichopteris elloretms, ibid. pi. ii. figs. 8-10. 

 1892. Pachypteris (Dichopteris) lanceolata, Fox - Strangways, Tab. Foss. 



p. 131. 

 1895. Pachypteris ovata, Krasser, Jahrb. geol. Reichs. "Wien. vol. xiv. p. 42. 



Type-specimens. The type-specimens of Phillips are said to be 

 in the York Museum, but I was unable to identify them among 

 the plants in that collection. The example figured by Saporta 

 [(73), pi. xiv. fig. 3] is in the Scarborough Museum (Text-fig. 28). 



Frond bipinnate ; rachis stout ; the linear pinnae bear thick 

 ultimate segments obliquely inclined to the axis, lanceolate or 

 of narrow oval form with an entire or slightly lobed margin ; 

 veins very indistinct, probably more than one in each pinnule. 



The material afforded by the East Yorkshire plant-beds is too 

 fragmentary and insufficient to enable us to give a satisfactory 

 diagnosis of the species to which the English specimens are 

 referred. It is not improbable that more than one specific type 

 is represented by the two examples shown in Text-figs. 27 and 28, 

 but in view of the meagre data and the probable variation in the 

 form of the pinnae and pinnules in one large frond, it is wiser to 

 refrain from any attempt at specific separation. 



The specimens which Brongniart named Pachypteris lanceolata 

 and P. ovata were obtained from a locality near "Whitby ; they 

 are specifically identical with the portions of fronds figured by 

 Phillips in 1829 as Sphenopteris ? lanceolata and Neuropteris 

 lavigata. Saporta, in discussing the English specimens, points 

 out that Brongniart's description of the pinnules as being without 

 visible veins, or as having a single vein, is not accurate, the 

 lamina of each ultimate segment being traversed by several veins. 

 The few fragments of Pachypteris obtained from English localities 



