Affinities of the Palaeozoic Seeds of the Conostoma Group . 47 
culties which beset the allocation to their exact place in phylogeny of the 
various structures and mechanisms which collectively constitute the seed. 
In the foregoing paper, the subject-matter of which is set forth in the 
table of contents (p. 1), we describe in detail two palaeozoic seeds, 
Conostoma oblongum , Will., and C. anglo -german icu m , sp. nov. ; these, with 
Gnetopsis , are provisionally placed in a separate group, the Conostomeae, 
ranking with the Physostomeae and Lagenostomeae as subdivisions of the 
larger class Lagenostomales. The seeds of the Conostoma type are com- 
pared with related forms, whilst diagnoses of the species and provisional 
diagnoses of the groups are given. In the more general parts of the paper 
especial attention is drawn to the arrangements for the reception and 
maturation of pollen found in the various seed types and to the peculiarities 
of the testa. 
University College, London, 
November , 1910. 
IX. Glossary of Terms employed. 
4 Blow-off. * An epidermal layer of presumed mucilage-containing cells, forming the outer- 
most investment of the testa (p. 14). 
Canopy. The apical portion of the hard testa consisting of a varying number of more or less 
fused members surrounding the free portion of the nucellus. 
Cupule. A free sheathing structure arising from the peduncle and investing one or more seeds. 
Doubly oblique or Assymetrically oblique. Applied to a section which is oblique both 
to any plane of symmetry and to the axis of the structure cut (p. 12). 
Flange. A ring-like projection of the integumental lining of the micropyle (p. 14). 
Lagenostome. A differentiated chamber at the apex of the nucellus formed by modification 
of the epidermis. The lagenostome is either included where the integumental micropyle forms an 
intermediate passage between its orifice and the exterior, as in Conostoma, or exserted where by 
upward extension of the lagenostome it communicated with the exterior direct, e. g. Lagenosto?na. 
Lens. The contracted tissue of the plinth which frequently remained attached to the base of 
the lagenostome (p. 20). 
Loculus. A chamber present in the canopy usually represented by a space, but probably filled 
with parenchymatous tissue continuous with the soft part of the integument lining the seed cavity, 
and into which the vascular strand passed. 
Major rib or angle. Applied to the large ribs or angles of a seed irrespective of their 
vascularity (p. 28). 
Minor rib or angle. Applied to the lesser ribs or angles of a seed where these latter fall into 
two categories only ; in other cases the terms secondary and tertiary are employed. 
Micropyle. The passage to the nucellar apex formed by the integument, which may be of 
three kinds, viz. a fimbriated micropyle of non-fused members, as in Physostoma ; an entire micro- 
pyle, as in Conostoma ; or an investing micropyle, as in Lagenostoma. 
Micropylar funnel. The lower portion of the micropylar tube where it expands to join the 
seed cavity (lagenostome jacket). 
Micropylar tube. The passage formed by the micropyle. 
Micropylar membrane. The integumental epidermis lining the micropyle — often found 
separated. 
Oblique. Applied to a section of which the plane is at right angles to a plane of symmetry 
but oblique to the axis of the structure cut. 
