LACCOPTfiKES. 



77 



V. 3661. Several piimse of a large spreading frond ; tlie reverse 

 piece of V. 3660. 



V. 3662. The upper part of a petiole, bearing several palmately 

 disposed puinse. Labelled by Leckenby " A new Pecopteris from 

 the Lower Sandstone and Shale near Scarborough." 



Other specimens .•— V. 3663, 39,297. 



Genus LACCOPTERIS, Presl. 

 [Presl, in Sternberg, Flor. Vorwelt, fasc. vii. p. 113, 1838.] 



1. Laccopteris polypodioides (Brongn.). 



2. Laccopteris Woodwardi (Leckenby). 



This genus was instituted by Presl in 1838 for some fragments 

 of fern fronds from the Keuper of StruUendorf, the type species 

 beiug named Laccopteris elegans. The generic characters are thus 

 defined : — 



" Trons pinnata, nervi primarii esourrentes, nervi secundarii 

 dichotomi ramulis furcatis simplicibusve, mediis in medio dorso 

 soriieris. Sori biseriales, fovese semiglobosae immersi, e sporangia 

 compositi." 



The same genus is described also by Goppert,^ Schenk,^ and 

 other writers. Schenk's account of the species of Laccopteris is 

 the fullest, and some excellent figures of the sori, sporangia, and 

 spores accompany his plates of the fronds of this genus. More 

 recently Zeiller^ has demonstrated the very close resemblance — 

 previously referred to by Schenk — between Laccopteris and the 

 recent genus Matonia. The published figures of the Ehsetic species 

 of Laccopteris represent the veins as diohotomiziug and not 

 anastomosing ; but an examination of specimens in the British 

 Museum and in the Palseontological Institute of Berlin has 

 convinced me that anastomoses are fairly frequent. A specimen of 



' Goppert (41), Lief. 1 and 2, pis. v. and vi. 



2 Schenk (67), p. 93, pis. xxii.-xxv. Vide also Schenk (88), p. 38, fig. 20. 



3 ZeiUer (85). 



