6 o 8 
Notes. 
Glaneuse, in the Haidinghen district, Pas de Calais, a piece of a ribbed 
Sigillarian stem, which presented a recognizable external surface, 
while, at the same time, the wood of the central cylinder was clearly 
preserved. The specimen may probably be referred to Sigillaria 
elongata ; the possible error does not exceed the difference which 
separates *9. elongata from -S’, scutellata. It was found by M. Ludovic 
Breton and his son, M. Eug. Breton, in a seam of coal known as the 
‘ Veine perdue/ The fragment measures ioo mm. in diameter and 
60 mm. in height, and the surface is traversed by seventy-two ribs, 
of which forty-eight are visible and twenty-four are hidden by a fold 
of the surface. The structure of the wood, which is in places 
perfectly preserved, agrees on the whole with that of a Diploxylon , 
and the primary xylem constitutes a continuous, centripetally developed 
corona. Externally, this is enclosed by a continuous zone of centri- 
fugal secondary wood, but the cambial and phloem regions, and also 
the central tissues, have completely disappeared. The carbonized 
peripheral region of the stem consists of sclerous tissue, of which the 
elements have thin brown walls and contain an amorphous yellow 
substance. 
The continuous corona is made up of ten to thirteen rows of large 
scalariform tracheides, without any free lignified elements internal 
to the primary xylem, which consists solely of tracheides without any 
interposed primitive fibres (‘fibres primitives’); in the latter respect 
the French specimen differs from one of the Diploxylon stems from 
the coal-measures of Oldham. The external face of the corona is 
characterized by very prominent teeth corresponding to the furrows 
of the external surface. The prominent teeth alternate regularly with 
the sinuses. The smallest xylem-elements are situated in the project- 
ing teeth. In a region of the corona, at some distance from the point 
of exit of a leaf-trace, the spiral tracheae are arranged in two superficial 
groups laterally placed in relation to the projecting teeth ; but in the 
immediate neighbourhood of the origin of a leaf-trace, the spiral 
elements form a median band in the middle of a sinus. The large 
tracheides of the primary wood represent its cauline portion (‘ partie 
rdparatrice ’). The leaf-traces arise from the external face of the 
corona, and each is detached from the middle of a sinus. The leaf- 
traces of every alternate sinus are cut almost at the same level, an 
arrangement which points to an almost regularly verticillate disposition 
of the leaves. 
