On the Structure and Affinities of the Palaeozoic 
Seeds of the Conostoma Group. 
BY 
F. W. OLIVER, F.R.S. 
Professor of Botany in the University of London, 
AND 
E. J. SALISBURY, B.Sc. 
Quain Student of Botany in University College , London. 
With Plates I-III and thirteen Figures in the Text. 
Contents. 
PAGE 
PAGE 
Introduction 
IV. 
Comparison with related 
CONOSTOMA OBLONGUM . . . 
5 
Types 
31 
1. Enumeration of Specimens 
5 
1. With Gnetopsis elliptica . . 
3 r 
2. General Features . . . . 
7 
2. With Physostoma . . . . 
35 
3. The Testa 
9 
3. With Lagenostoma .... 
35 
4. The Vascular System . . 
• 13 
V. 
Classification and Diagnoses . 
36 
5. The Soft Integument . . 
• 13 
6. The ‘ Blow-off’ Layer . . 
. 14 
VI. 
The Pollination Mechanisms 
7. The Nucellus 
. 16 
of the Lagenostomales . . 
38 
8. The Lagenostome and Plinth 
16 
VII. 
General Discussion on the 
CONOSTOMA ANGLO-GERMANICUM 23 
Testa 
41 
i. Enumeration of Specimens 
• 23 
2. General Features .... 
. 24 
VIII. 
Conclusion and Summary . . 
45 
3. The Testa 
4. The Vascular System . . 
. 29 
IX. 
Glossary of Terms employed . 
47 
5. The Nucellus 
• 30 
X. 
Literature cited 
48 
6. The Lagenostome . . . 
. 30 
7. The Plinth 
XI. 
Explanation of Plates I— III . 
48 
Index to Text-Figures. 
PAGE 
PAGE 
1. Plottings of sections of C. oblongum 
on 
8 . Longitudinal and transverse plottings 
vertical diagram ...... 
6 
of C. anglo-germanicum .... 
25 
2. Plottings of C. oblongum on transverse 
9. Vertical restorations of C. anglo-ger- 
diagram 
7 
manicum 
26 
3. Restorations of C. oblongum . . . 
8 
10. Transverse restorations of C. anglo- 
4. Testa of C. oblongum cut obliquely 
10 
germanicum 
27 
5. Restoration of the lagenostome 
of 
11. Hypothetical restoration of Gnetopsis 
C. oblongum 
T 7 
elliptica 
34 
6. Sculptured cells of lagenostome 
of 
12. ‘ Pollen-chambers ’ of Lagenostomales 
39 
C. oblongum 
18 
13. Transverse restorations of apices of 
7. Restorations of the plinth and con- 
Physostoma and the two species of 
tents 
21 
Cono stoma «, 
42 
[Annals of Botany, Vol. XXV. No. XCVII. January, 1911.] 
B 
