54 NILSSONIA.. 



Type. Several specimens of leaves. 

 Dunker defined the species as follows : 



" Pterophyllum fronde pinnate vel, rarissime quidem, profunde 

 pinnatifida, pinnis alternis approximatis sub-obliquis irregularibus, 

 oblongo-ovatis, vel quadratis vel rotundatis, infimis subdecurrenti- 

 bus, nervis crebris tenuibus instructris, rhachi (suptereti ?) 

 longitudine striata." 



The specimens figured by D linker from the North German 

 Wealden beds show a considerable variation in size and form ; this 

 variable character is also well brought out in the later and more 

 perfect figures in Schenk's monograph. Such a specimen as that 

 represented by Dunker in pi. i. fig. 7 l must probably be regarded 

 as a leaf seen from the under side, thus showing a Pterophyllum- 

 like appearance. Schenk draws attention to the apparent lateral 

 attachment of the segments in some of the specimens which are 

 seen from the under surface, but notes that there can be no doubt 

 as to their actual insertion on the upper surface of the axis. 

 Schimper includes this variable Wealden species in his genus 

 Anomozamites, and Schenk accepts this determination. Peyton has 

 previously recorded the species in the English Wealden beds, but 

 no detailed descriptions or figures accompany his note. Nathorst 

 records from Japan specimens of what is most probably the same 

 species as the English and North German forms ; he refers to 

 a previous paper 2 in which he pointed out the true Nilssonia 

 character of Bunker's species, the segments being attached to the 

 upper face of the rachis, and not laterally as in Pteroplnjllum or 

 Anomozamites. A leaf fragment closely resembling the present 

 species is figured by Schenk 3 from Persia as Anomozamites minor, 

 Schimp. In Yokoyama's recent contribution on Mesozoic plants 

 from Kozuke, etc., several specimens are referred to this species 

 on the authority of Nathorst ; the figures suggest a lateral attach- 

 ment of the unequal segments, but possibly the leaves are shown 

 with the under side uppermost. Nathorst's figures of this species 

 from Japan represent typical Nilssonia fronds. 



1 (A. 2), Wealdenbildung. 



2 (2), p. 82. 



3 (A. 7), Bibl. bot. vi. pi. v. fig. 21. 



