692 PROFESSOR A. C. SEWARD ON 



veins. This specimen is in all probability specifically identical with the Culgower 

 fronds referred to Pseudoctenis eathiensis. It might be legitimate to include such 

 fronds as show the characters of Ctenis except as regards anastomosing of the veins in 

 that genus, on the analogy of the occasional occurrence of undoubted Glossopteris leaves 

 in which venation reticula are very rare ; * but on the whole it is more convenient to 

 adopt a distinctive generic name such as Pseudoctenis. 



Pseudoctenis eathiensis (Richards). (PI. IV. figs. 62, 62A, 67, 67A ; PL VII. 

 photos. 11, 12; PI. VIII. photo. 32; PI. X. photo. 45.) 



1884. Zamites eathiensis, Richards, B. Phys. Soc. Edin., p. 117. 



Photo. 45, PI. X., shows part of the large specimen figured by Hugh Miller 

 as Zamia, and made the type of a new species by Richards. This example, with a 

 rachis 27 cm. long and incomplete at each end, no doubt represents the lower portion 

 of a very large frond. The linear pinnae, only portions of which are preserved, show 

 several parallel veins, approximately 1 mm. apart, very distinctly ; there are no un- 

 doubted lateral connections between the parallel strands. The bases of some of the 

 pinnae show that the lower margin was decurrent on the rachis. The rachis is partially 

 petrified, and in a transverse section it is possible to recognise hypodermal thick-walled 

 tissue with indications of some secretory canals, as in the axis of recent Cycadean fronds. 

 Another specimen figured by Miller in his Testimony of the Rocks, fig. 135, which 

 Richards speaks of as possibly Ctenis falcata L. & H., is, I have no doubt, identical 

 with the larger example represented in photo. 43. The specimen, part of which is 

 reproduced in photo. 11, PI. VII., has a length of 26 cm., the upper part of the rachis, 

 not included in the photograph, being bent almost at right angles to the lower and 

 thicker part. The bases of the pinnae agree with those of the apical portion of the 

 frond shown in photo. 32, PI. VIII. In photo. 32 the bases of some of the pinna? 

 slightly overlap the axis of the frond and afford some indication of a basal callosity 

 such as occurs in the fronds of Ceratozamia mexicana and other recent Cycads. This 

 specimen bears a striking resemblance to fronds of Zamites Buchianus (Ett.), a Wealden 

 species, but the venation of the Culgower species is much coarser, and the bases and 

 manner of attachment of the pinnae are different. A small piece of a similar frond is 

 seen in fig. 62, PI. IV., which illustrates the characteristic bases of the linear segments; 

 in one of the pinnae (fig. 62A) the veins show forking and there is a suggestion of a 

 cross-connection. The specimens represented in fig. 62 and photo. 11 are from the lower 

 part of fronds, where the pinnae are given off at a much wider angle than in the more 

 apical part {e.g. photo. 32). In the best example of this type, reproduced in photo. 32, 

 PI. VIII., the apical linear segments are almost parallel to the rachis; the longest 

 reaches a length of 1 7 cm. ; the lamina is gradually tapered towards a slender apex 

 and contains about eight or nine veins per 5 mm. of lamina. The form of the base of 



* Seward (10), p. 508. 



