Notices of Memoirs—Graptolite Zones. 473 
confidence be extended to a line joining Selby, Thorne, Haxey, and 
Owthorpe, but the quality and thickness of the coal cannot be foretold. 
There is no conclusive evidence to show whether, north of Thorne, 
the Barnsley Coal will take on the inferior character which it assumes 
north-east and east of Wakefield under the name of the Warren House 
Coal, and whether the thinning out of the Top Hard Coal observable 
in some of the collieries south of Mansfield will continue to the east. 
A further extension north of the Ouse, east of the Trent, and south- 
east of Owthorpe is probable, but it is important to bear in mind how 
much there must be of conjecture in any conclusions arrived at from 
the slender evidence at present available. 
TV.—Tue Grarroniric Zones oF ton Satopran Rocks oF THE CAUTLEY 
AREA NEAR SepBeRGH, YorKsHrrE. By Miss G. R. Warnzy and 
Miss EK. G. Wetcu. 
EK haye obtained the following zones in the Ludlow Rocks in 
descending order :— 
1. Monograptus leintwardinensis (Hopk.) : . Lower Bannisdale Slates. 
2. Monograptus Nilssoni (Barr.) . : . 5 ' aes pone Ae 
3. Monograptus vulgaris (Wood) . : : - M. Coldwell Beds. 
In the Wenlock the following zones have been found in descending 
order :— 
( L. Coldwell Beds. 
1. Cyrtograptus Lundgrent (Tullb.) | Brathay Flags 
Cyrtograptus Linnarssoni (Lapw.) \ ‘ ; 
= { Cyrtograptus symmetricus (Elles) : ~ Brathay Flags. 
3. Monograptus riccartonensis (Lapw.) . : . Brathay Flags. 
4. Cyrtograptus Murchisoni (Carr) . 5 . Brathay Flags. 
These zones are comparable with those discovered by Miss Elles! 
and Mrs. Shakespear’ in Wales and the Welsh Borderland!; though 
we have not yet succeeded in finding all the zones which they record 
we hope shortly to establish them in this area. 
V.—SrrvcruraL PerriractIons FrRoM THE MesozoIc, AND THEIR 
BEARING ON Fossiz Prant Impresstons. By Miss M. C. Sropxs, 
DScee bh... Fels. 
/Y\HE paper dealt with the importance of the structural petrifactions 
in the Carboniferous, e.g. exposure of the true nature of so 
many supposed ‘ferns’; with the need of similar petrifactions from 
beds of Mesozoic age; and the danger of inferences drawn from plant 
impressions, e.g. untrustworthiness of many of Heer’s and Ettings- 
hausen’s systematic determinations. 
The discovery of true petrifactions in the Cretaceous, the nature of 
the flora contained in the nodules, and unusual points in its composition 
were considered. Special illustrations of its interest are: Yezonia, a 
new type of which the external appearance gives no clue to its nature ; 
the discovery of the first-known flower with its anatomy petrified; 
and of the internal anatomy of the leaves of Wilssonia, long well known 
as impressions. 
1 Q.J.G.S., 1900. 
