of Bennettites gihsonianus , Carr. 429 
fragment supplies an instructive fracture, which passes obliquely 
through a fructification. 
4. Of a large series of slices, the material employed in Car- 
ruthers’ investigation, partly supplied by Hooker. These are 
sections in various directions through the fructifications. From 
the character of the stone and the structure I am satisfied that 
a slice, without a label, showing the transverse section of pith 
and woody cylinder, is one of this series. 
5. Lastly, of the slices recently taken by myself from 
the fragment at Kew ; the chief of these are preserved 
at Kew ; a few duplicates have remained in my posses- 
sion. 
Note. In presence of the fact that so many stems of Bennettiteae 
have been found only in secondary places of deposit, it is very 
necessary to determine with all possible exactness the place of origin 
of all important specimens. I therefore visited Luccomb Chine in 
August 1889. The chine is a deep ravine entirely in the Lower 
Greensand. The lowermost bed of the formation on the sea-shore is 
rather less deeply cut into than the beds above it, and forms a 
nearly vertical wall from two to three metres high, of dark colour and 
sandy character. It is full of green grains of glauconite and small 
bits of iron pyrites, the iron giving rise to an ochreous coating on the 
surface in moist spots, and it contains an unusual quantity of small 
fragments of coal which deserve closer examination, though it would 
be necessary for this purpose to obtain unweathered material from 
within the bed. It also contains concretions like those of the Loess, 
which weather out and then lie on the sand of the shore among the 
fragments of flint ; comparison of the products of weathering with 
the bed leaves no doubt that the concretions come from the bed. 
If we break up the concretions we usually find at the centre of them 
a fragment of coniferous wood in good preservation, and sometimes 
covered with only a thin crust of stone. The wood is of a grey 
colour as long as it is quite fresh, but it passes into chocolate-brown 
as soon as it begins to weather. The material of petrifaction is 
calcium carbonate and tricalcium phosphate. 
The original block of Bennettites gihsonianus found at the same 
spot greatly resembles these concretions, and the rock adhering to it 
here and there has the same composition, but its outer surface is 
coloured ochre-brown all over, in consequence probably of being rich 
H h 
