90 Notes and Comments. 
PERMIANS OF DURHAM. 
Part 5 of Volume IV. of the Proceedings of the University 
of Durham is entirely occupied by a substantial and valuable 
memoir dealing with the Stratigraphy and Tectonics of the Per- 
mians of Durham (Northern area). Illustrated by diagrams 
and photographs, Dr. Woolacott’s paper well summarises all 
previous papers on this difficult series of rocks, and in addition 
contains particulars of much of the author’s own field work. 
After dealing with the ‘ foundation’ (the Coal Measures floor) he 
refers to the lithological divisions, marl slate, Upper, Middle and 
Lower Limestones, paleontology, thrusting, breccias, cellular 
structures, etc. Altogether it is a very creditable piece of 
work. 
STRUCTURE OF MESOXYLON. 
By the aid of many magnificent photographic reproductions 
of microscopic sections of coal-balls, from Shore, Lancashire, 
Dr. D. H. Scott gives a valuable contribution to paleeobotany in 
The Annals of Botany, Vol. XXVI., No. CIV. His paper is 
on ‘ The Structure of Mesoxylon Lomaxii and M. poroxyloides,’ 
and he concludes that the genus comes very near Cordaites, as 
shewn by the characters of the pith and wood, and further 
indicated by those of the associated leaves. The affinity with 
Poroxylon is somewhat more remote, and the genus is best placed 
in the family Cordatteae ; it is at present definitely distinguished 
from Cordaites only by the presence of centripetal wood in 
the stile of the stem. Mesoxylon thus forms the last link in 
the chain of fossil types connecting the Pteridosperms with 
the typical Cordaites of the Upper Palaeozoic. 
MASS OF ANHYDRITE AT HARTLEPOOL. 
At arecent meeting of the London Geological Society, Mr. 
. T. Trechmann read a paper on “a Mass of Anhydrite in the 
Magnesian Limestone at Hartlepool.”’ Apparently the har- 
bour at Hartlepool owes its existence to the erosion of a mass 
of anhydrite of great thickness, proved by borings and other 
evidence to exist in close proximity to the Upper Magnesian 
Limestone upon which the towns of Hartlepool and West 
Hartlepool are built. The anhydrite is included in, and repre- 
sents the time-equivalent of part of the Middle and the greater 
part of the Upper Limestones. The contrary view, that the 
anhydrite belongs to the overlying red beds here faulted down, 
is said to be erroneous. Very large quantities of anhydrite were 
originally deposited with the Magnesian Limestone, the subse- 
quent hydration and removal of which is chiefly responsible for 
the collapse, degradation, brecciation, and other alterations 
that are such obvious features of the formation in its present 
condition. 
Naturalist, 
