THE JrjRASSIC FLORA OF SUTHERLAND. 691 



vary in breadth from about 4 cm. to rather less than 1 cm. The typical form is that 

 represented in photo. 19, PI. VII., and photo. 26, PI. VIII. . in which the linear pinnae 

 are gradually tapered to the apex, the upward curve of the lower edge of the lamina 

 at the tip being stronger than that of the upper margin ; the pinna? are contiguous at 

 the base, which may be slightly expanded. The veins are usually obscure, but in the 

 fragment seen in photo. 26 they are clearly shown ; there are approximately four veins 

 to a millimetre of lamina. Photo. 20, PI. VII., illustrates a form not uncommon in the 

 Jurassic beds of the Yorkshire coast and at Stonesfield, in which the pinnae are close 

 together, relatively shorter, and more abruptly contracted at the apex. The variation 

 met with in fronds referred to this species is well illustrated in PL III. of the second 

 volume of my Jurassic Flora. 



This very widely spread species has recently been recorded by Nathorst from the 

 Antarctic regions # and by myself from Turkestan and the Caucasus, t 



Williamsonia sp. (PI V. fig. 99 ; text-fig. 12, B.) 



The imperfect specimen represented in fig. 99 consists of portions of what seem to 

 be partially decayed fibrous bracts ; their position suggests that they formed a 

 protecting envelope to a fertile shoot as in the flowers of Williamsonia and Bennettites. 

 This is the largest example among the few fossils of this type contained in the Gunn 

 collection. In another specimen (text-fig. 1 2. B) the bracts are more closely arranged, 

 as in a closed bud borne on a branched axis. The form of the bracts, their texture, 

 and disposition favour the view that these fragrnentary fossils are the remains of 

 fertile shoots of a Williamsonia. 



A comparison may be made with Blastolepis otozamitis described by Zigno,| with 

 Williamsonia cretacea Heer,§ W. microps Feist., || and W. oregonensis Font. IT 



2. Oycadophyta incertae sedis. 



Pseudoctenis, gen. nov. 



The genus Ctenis of Lindley and Hutton, as represented by the type-species 

 C. falcata** is characterised by the fairly frequent anastomosing of the parallel veins of 

 the broadly linear segments ; the pinnae are laterally attached as in Pterophyllum, the 

 lower margin is decurrent, and the upper border of the lamina curves slightly upwards 

 as it joins the stout rachis. The venation is usually coarser than in Pterophyllum, 

 and the longer spreading pinnae give the fronds a habit less formal and rectangular 

 than that of most Pterophyllum leaves. In the Wealden Flora, vol. ii. } I described 

 a specimen as ? Zamites sp.tt which agrees very closely in habit with Ctenis falcata 

 L. & H., but is distinguished by the absence of lateral anastomoses between the 



* Nathorst (04). t Seward (07). \ Zigno (85), pi. xlii. 



S Heer (82), pis. xii., xiii. || Feistmantel (80), pi. xli. IT Ward (05), pi. xxix. fig. 6. 



** Lindley and Hutton (34), pi. ciii. tt Seward (95), p. 89, fig. 5. 



TRANS. ROY. SOC. EDIN., VOL. XLVII. PART IV. (NO. 23.) 102 



