TACHYPTERIS. 



175 



specimens. 1 It is possible that Pachypteris (Dichopteris) Visianica 

 (Zigno) is specifically identical with P. lanceolata. An interesting 

 example of Pachypteris has been described more recently by 

 Krasser from the Chalk of Lesina under the name P. dalmatica.* 



Text-fig. 27. 



This specimen (Whitby Museum, No. 2376) represents an 

 imperfect pinna bearing thick pinnules, reaching a length of 

 1 cm., in which the veins cannot be detected. 



Text-fig. 28. 



The original of "Williamson's drawing published by Saporta. 3 

 As in the Whitby specimen, the veins are not visible ; in 

 "this example several of the segments have a slightly lobed 

 margin, and bear a striking resemblance to those of Scleropteris 

 fomelii, Sap. 4 



1 Zigno (56), pis. xii. and xiii. 



2 Krasser (95), p. 47, pi. ii. 



3 Saporta (73), pi. xlv. fig. 3. 

 * Loc. cit. pi. xlvii. 



