Yol. 69.] THE CLEVELAND DISTRICT OF YORKSHIRE. 245 



also somewhat more divided than the examples figured by Heer. 1 

 The Yorkshire specimens agree fairly well with the original 

 rather incomplete example figured by Saporta. 2 



Specimens from the grey shales have furnished good cuticular 

 preparations, after repeated treatment with Schultz's solution (see 

 fig. 5, p. 244). The cuticles are of the usual Baiera type : they are 

 very thick, and those from the two sides of the leaf are different. 

 One epidermis, with the thicker cuticle, was composed of cells 

 with a more or less longitudinal arrangement but showing no 

 traces of veins. It possessed very few stomata, and almost every 

 cell was enlarged to form a papilla or central hump. These 

 appear in preparations in surface-view as round spots on the cells 

 {fig. 5 A) ; but their nature is seen in side view, as shown in fig. 5 C. 

 The cuticle of the other epidermis is somewhat thinner, the cells 

 are rounded or hexagonal, and stomata are frequent, although they 

 do not occur abundantly. The last-named were somewhat deeply 

 sunk, and the guard-cells are seldom clearly visible. They are 

 surrounded by five or six subsidiary cells of a darker colour than 

 the other epidermal cells. Their form and arrangement, which 

 is rather characteristic of leaves of the Ginkgo type, is seen in 

 fig. 5 B. The cells of the lower epidermis are also characterized 

 by small papillate outgrowths. 



CZEKANOWSKIA MURRAVANA (Lindl. & Hutt.). 

 [' Foss. Plor.' vol. ii (1833-35) pi. cxxi.] 

 This form, which is present in most of the Yorkshire plant-beds, 

 is well represented at Marske in the sandstones and shales. The 

 remains of the narrow leaves are usually more or less superimposed 

 one on the other; they are *75 to 1 mm. broad, and, although indi- 

 cations of forking may be occasionally made out, such are not 

 commonly seen. 



Coniferales. 



Taxites zamioides (Leckenby ex Bean, MS.). 

 [Q.J. G.S. vol. xx (1864) p. 77 & pi. viii, fig. 1.] 

 This species, which is common in the Lower Estuarine Beds at 

 Whitby, is represented in the collections here described by some well- 

 preserved specimens. The slender twigs bear a number of lanceolate 

 leaves, spirally disposed on the stem but assuming a distichous 

 arrangement. The individual leaves have acute apices, and exhibit 

 a marked contraction at the base, being only about 1 mm. broad at 

 the point of insertion. They show a very distinct midrib. The 

 leaves are rather larger than those of the usual "Whitby form. 

 One carbonized specimen of a separate leaf occurring in the grey 

 shale has furnished excellent preparations of the cuticle. The 

 upper side is composed of more or less uniform cells of a some- 

 what compressed rectangular shape, and quite devoid of stomata. 



1 See also Krasser (05) p. 606. 



2 Sapor ta (73) p. 464 & pi. lxvii, fig. 1. 



