122 Proceedings of the Royal Physical Society. 



rachis. The veins are sufficiently distinct, as shown in the 

 drawing. No species previously described seems to possess 

 characters corresponding with the above. P. angustifolius 

 (Eichw.) is perhaps the nearest, but it is much smaller, the 

 leaflets in Eichwald's figure (Leth. Possica, vol. ii., tab. ii., 

 fig. 7), which is of natural size, having but half the length 

 and width of these ; their greatest width occurs near the base, 

 where they are therefore most approximated, and from which 

 they gradually narrow outwards. The fragmentary specimens 

 figured by Heer (Peitr. zur Foss. Flora Spitzhergens, tab. vii., 

 f. 8-11, viii., 2e, 5 ; Peitr. z. Jura. Fl. Ost. Sihir. u. d. Amur- 

 landes, tab. xxvi., f. 11 ; Peitr. z. foss. Fl. Sib. u. d. Amurl.y 

 tab. v., f. lib.) with this name are somewhat difficult of 

 determination. There can therefore be little hesitation in 

 assigning to the leaf, derived from the same locality as the 

 last, the position of a new species, which I have dedicated to 

 the memory of Dr Heer. 



? Ctenis falcata — L. and H. 



" Zamia," Hugh Miller, Test, of the Rocks, p. 478, fig. 135. 



I am unable to separate from this well-known Scarborough 

 species the leaf here figured from the Oolite of Helmsdale. 

 The specimen is of the same size as the Yorkshire plant ; its 

 leaflets have the same form and arrangement, the same mode 

 of insertion, and apparently the same venation. Division 

 and anastomosis of veins are not indeed to be detected, but 

 similar divergence at the base is seen, and the veins are as 

 large and conspicuous as they usually are in English speci- 

 mens, and of corresponding number. The decurrence of the 

 leaflets behind one another at the base, and a slight narrow- 

 ing sometimes beyond the insertion, are equally characteristic. 

 The leaflets, perhaps, are closer together, and may be a little 

 more oblique than they are, as a rule, in the Yorkshire 

 specimens, which, however, vary in these respects. As usual 

 in the latter, their apices are not seen. The upper part of 

 the specimen will be observed closely to correspond with 

 Lindley and Hutton's figure (" Fossil Flora," vol. ii., tab. 103). 

 In the meantime, therefore, it may be regarded as continuing 

 Ctenis falcata to a higher level in the Jurassic system. 



