6 DESCRIPTIVE CATALOGUE 



1910. Weichselia reticulata, Zeiller, Comptes Rend. Acad. Sci. 

 Paris, p. 1488. 



191 1 . Weichselia reticidata, Berry, Maryland Geol. Surv. Low, Cret., 

 various pp. in lists. 



Diagnosis. Most pinnules entire, with rounded apices, but 

 towards the ends of the pinnae tending to be more triangular 

 with slightly pointed apices. Network of finer veins seldom 

 visible, but when preserved the finer meshes about 3 to 4 per 

 millimetre. In sandstone casts the pinnules often appear to be 

 inclined at an angle toward the pinnae, but this was probably 

 not the case in life. Sori very rare, round, when present lying 

 in double rows, one on either side of the mid-rib. 



HORIZON (of described specimen). Lower Grecnsand. 

 LOCALITY. Yentnor, Isle of Wight. 



GENEEAL DISTRIBUTION. Very widely distributed throughout 

 the Neocorrtian : recorded from Itussia, Austria, Sweden, 

 Germany, France, England, North and South America, etc. 

 Hare as high up as the Gault. 



TYPE. Small fragments of pinnules, first recorded by Stok s 

 & Webb, 1824, first diagnosed as WeichteKa by Stiehler, lSr>7. 

 The actual type-specimens appear to be lost. 



Seward (1894) gave a detailed record of the history of this 

 species under the name WticJiselia MantelH, which it is un- 

 necessary to recapitulate, particularly as Gothan (1910) has 

 brought the subject well up to date in a monographic treatment 

 of the species in Potonie's series of l Abbildungen." Nathorst 

 (1891, p. 19), Seward (1894, p. 116), and others have laid stress 

 on the inclination of the pinnules toward the axis of the pinna 

 as a characteristic of the fern; 1, however, agree with Gothan 

 (p. 0) that this was not a peculiarity of the living plant, but a 

 probable result of its condition before being enclosed in the 

 coarse matrix of the sandstone in which this appearance is 

 now generally to be seen. In support of this view it is note- 

 worthy that the specimens found in fine-textured shale do not 

 show this feature. The general appearance of the fronds is 

 " xerophytic," the pinnules apparently having been unusually 

 thick and leathery. As Ward (1899, p. 652) points out, the 

 nature of the imprint and the amount of carbonaceous matter 

 sometimes left on the impression support this view ; as also 

 does the frequent occurrence of specimens in coarse sandy 



