Vol. 69.] THE CLEVELAND DISTRICT OF YORKSHIRE. 233 



WiLLIAMSONIA WHITBIENSIS NathOTSt. 



[' Palfeobot. Mitt. 9 ' K. Svenska Vetensk.-Akad. Handl. vol. xlvi (1911) No. 4, 

 p. 9, & pi. ii, figs. 1-15, pi. iii, figs. 2-7.] 



The presence of this type of ' flower ' in the Marske heds is 

 •rendered probable by the examination of a crushed and rather 

 badly-preserved specimen in my collection. The cup-like base of 

 the ' flower ' is seen and was apparently sessile, but the free 

 portions of the sporophylls cannot be clearly made out. At 

 intervals, however, we can distinguish double rows of depressions 

 running upwards and occupying the positions in which we should 

 expect to find the sporangia. There seems to be little doubt that 

 these double rows of depressions (or in some cases elevations) 

 represent the original synangia (functional or reduced), but the 

 •specimen is not sufficiently well-preserved for us to be certain of 

 the details of structure. The cup of the flower would probably be 

 about 4 or 5 cm. across, and it is thus considerably smaller than 

 that of Williamsonia spectabilis. There seems to be little reason to 

 •doubt that this is a specimen of Williamsonia whitbiensis Nathorst. 



Williamsonia sp. Eemale strobilus. 



A single specimen of a female strobilus has been found in the 

 grey shales. Its outline is very indefinite, and the point of attach- 

 ment cannot be clearly made out. It is roughly circular, and at 

 one side the scales show an elongated shape probably indicating 

 proximity to the base. The whole structure is composed of a mass 

 of well-defined hexagonal bodies, the heads of the interseminal 

 scales. These were apparently of a firm, if not woody, texture 

 and stand out clearly ; no traces of micropylar tubes are seen 

 between them. When some of the scales are removed and treated 

 with Schultz's solution, a certain amount of the structure becomes 

 visible. The heads of the scales seem to be composed of a number 

 of cells having very thick walls, and displaying a roughly radial 

 arrangement. The arrangement of the cells is, however, not so 

 regular as in the examples of Williamsonia leckenbyi (joecten) 

 figured by Prof. Nathorst * ; the cells are also more strongly 

 thickened than in that form. 



The absence of micropylar tubes and the strongly thickened 

 nature of the scales suggest that this was possibly an old strobilus 

 from which the micropylar tubes had disappeared after fertilization. 

 In the absence of further details of structure it is impossible 

 to assign to the specimen any specific name. No definite male 

 strobili have been found in the same bed, but some portions of 

 male sporophylls of apparently a new type have been found. The 

 latter are not yet sufficiently known to merit description in this 

 paper. 



Other fragmentary examples of Bennettitalean strobili have 

 also been found in the sandstones. 



1 Nathorst (092) p i. iii, fi gs . 8-10. 



r2 



