XXVIl] LOMATOPTERIS 545 



characterised by a prominent and broad rachis giving oflf 

 alternate linear pinnae bearing bluntly rounded, contiguous 

 and basally concrescent pinnules having a thick or revolute 

 border and a central rib. The lateral veins are visible in the 

 ultimate segments of Kurr's fossil. Saporta^ has described 

 several species, which he refers to Schimper's genus, from 

 French Jurassic strata: it is, however, difficult to recognise 

 some of the examples represented in his illustrations as speci- 

 fically distinct forms. This author notices the resemblance of 

 Lomatopteris to Thinnfeldia, not only in habit but in the 

 structure of the epidermal cells^. In Lomatopteris and in 

 Thinnfeldia the cells have straight and not sinuous walls 

 and the slightly sunken stomata are surrounded by a ring 

 of epidermal cells. Salfeld' has recently described portions 

 of fronds from Jurassic rocks of South- West Germany, which 

 he identifies as Lomatopteris jurensis. He disagrees with my 

 ^^ew that Lomatopteris does not differ sufficiently from Thinn- 

 feldia to be accorded generic autonomy, chiefly on the ground 

 that the folded-over edge of the pinnules is a distinguishing 

 feature of Lomatopteris. There is, however, no difference, in 

 appearance at least, between the leaflets of some species of 

 Thinnfeldia, e.g. T. rhomboidalis from Liassic rocks of England*, 

 and those referred to Lomatopteris. In a later paper, Salfeld' 

 describes some Portlandian fragments from North Germany as 

 Lomatopteris Schimperi, identifying them with a Wealden fossil 

 of somewhat doubtful affinity, which Schenk^ makes the type 

 of his species. The Portlandian specimens are described as 

 tripinnate, with thick decurrent obtusely terminated pinnules 

 with a revolute edge. The general form of the frond is very 

 similar to that of L. jurensis. Salfeld publishes a photograph 

 of a large specimen which he describes as fertile and a drawing 

 of a piece of a pinna : the latter is reproduced in fig. 360, B. 

 He speaks of sori occurring in two rows, probably attached to 

 lateral veins, in the groove between the midrib and the revolute 

 edge of the lamina. The sporangia are described as " nicht 



1 Saporta (73) A. ^ Schenk (67) A. " Salfeld (07) p. 192. 



* Seward (04) p. 34, fig. 2, PI. iv. » Salfeld (09). 



6 Schenk (76) PI. xxvi. fig. 7. 



