694 PROFESSOR A. C. SEWARD ON 



hesitation with the characteristic Wealden type Z. Buchianus recorded from the south 

 of England, Japan, the Potomac of Virginia, N.W. Germany, and elsewhere.* 



Zamites Carruthersi Seward. (PI. X. photo. 43.) 



1884. Podozamites Milleri, Richards, Proc. R. Phys. Soc. Edin., p. 120. 



1895. Zamites Carruthern, Seward, Wealden Flora, vol. ii. p. 86, pi. vi. figs. 2-4. 



Photo. 43, PI. X., shows part of the specimen which Miller figured as one of his 

 Cycadean fronds included under the general designation Zamia : the pinnae are not in 

 reality so much contracted at the base as would appear from Miller's drawing. A 

 comparison of this specimen with those from the Wealden of Sussex, which I described 

 as Zamites Carruthersi, \ leads me to refer the .Sutherland plant to that species; the 

 specimens agree in the form and venation of the pinnae, which are characterised by the 

 presence of numerous fine veins radiating from the base as in Otozamites, and by the 

 clean-cut base as seen at a in the photograph. As pointed out in the description of 

 the type-specimens, the pinnae bear a close resemblance to those of certain recent species 

 of the South African genus Encephalartos, e.g. E. longifolius Lehm. 



Pterophyllum, Brongniart. 



In discussing the application of this generic name, Zeiller \ has pointed out that the 

 description of fronds of the Pterophyllum type under different sub-generic or generic 

 designations is in most cases based upon characters which are too variable or artificial 

 to justify generic rank. His use of Brongniart's genus in a wide sense is, I believe, 

 a sound course to follow. 



Pterophyllum Nathorsti (Seward). (PI. IV. figs. 60A, 61, 6lA; PI. V. figs. 79, 86, 

 86A; PI. IX. fig. 36 ; PI. X. fig. 44 ; text-fig. 13, A, B.) 



1871. Pterophyllum Dunkerianum, Schenk (pars), Palseontographica, Bd. xix., pi. xxxiv. fig. 5. 

 1900. Dioonites Nathorsti, Seward, Jurassic Flora, vol. i. p. 239. 



The type-specimen of Dioonites Nathorsti from Yorkshire in the Sedgwick Museum, 

 Cambridge, is, I believe, specifically identical with the specimen figured by Miller in 

 The Testimony of the Rocks as Phlebopteris and reproduced natural size in photo. 44, 

 PI. IX., also with smaller specimens more recently acquired from the Sutherland beds. 

 Miller's specimen has a rachis preserved as a ridge 2 mm. broad bearing laterally 

 attached pinnae, the longest of which reaches a length of 5 "5 cm. In a few cases the 

 apex is preserved, showing a slightly truncate form with the lower margin of the lamina 

 more strongly curved than the upper. The linear pinnae vary somewhat in breadth, 

 from 3 to 4 mm. ; the veins are indistinct, but there appear to be about three to each 

 millimetre. The smaller specimen shown in text-fig. 13, A, B, in which both upper and 

 lower surfaces are seen, demonstrates the lateral attachment of the pinnae. The rachis 



* Seward (95), p. 79. See also Salfeld (07 2 ). t Seward (95), p. 86, pi. vi. figs. 2-4. J Zeiller (03). 



