FOSSIL I'LANTS. 



653 



ACERINE*. 



Genus 12. Acer. One or two species in the tertiary 

 beds. 



CONIFERS. 



Tli^ wood only laimtm, 

 fienus 13. Pinites. Axis composed of pith wood in 

 concentric circles, bark and medullary rays, 

 but -with no vessels, walls of the woody fibre 

 reticulated. 

 Three species in coal formation. 

 Genus 14. Arazuxma. Axis composed of pith wood in 

 concentric circles, bark and medullary rays. 

 One or two species in coal measures; one 

 in lias. 

 Fruit or brandies, and leaves, rnily Imoion. 

 Genus IS. Pinus, Leaves growing two, three, or five 

 in the same sheath; cones composed of im- 

 bricated scales, which are enlarged at their 

 apex into a rhomboidal disk. 

 Nine species in the tertiary strata. 

 Genus 15. Ahks. Leaves solitary, inserted in eight rows 

 in a double spine, often unequal in length 

 and distichous; cones composed of scales, 

 without a rhomboidal disk. 

 One species. 

 Genus 17. Taxites. Leaves solitary, supported on a 

 short petiole, articulated and inserted in a 

 single spine, not very dense, distichous. 

 Five species in tertiary beds. 

 One species in oolitic formation. 

 Genus 18. Podocarpus. Leaves solitary, much larger 

 than in the last genus, sharp, pointed, flat, 

 with a distinct midrib. 



One species in the tertiary formation of 

 Aix. 

 Genus 19. Voltiza. Branches pinnated, leaves inserted 

 all round the branches, sessile, slightly de- 

 current or dilated at the base, and almost 

 conical, often distichous. Fruit forming 

 spikes or loose cones composed of distant 

 imbricated scales, which are more or less 

 deeply three-Iobed. 



Four species in the new red sandstone. 

 Genus 20. Juniperites. Branches arranged irregularly, 

 leaves short, obtuse, inserted by a broad base, 

 opposite, decussate, and arranged in four 

 rows. 



Three species in the tertiary beds. 

 Genus 21. CupressUes. Branches arranged irregularly; 

 leaves inserted spirally in six or seven rows, 

 sessile, enlarged at their base; fruit consist- 

 ing of peltate scales, marked with a conical 

 protuberance in the centre. 

 One species in the new red sandstone. 

 Genus 22. Tliuja. Branches alternate, regularly arranged 

 upon the same plane; leaves opposite, decus- 

 sate in four rows; fruit composed of a small 

 number of imbricated scales, terminated by 

 a disk, which has near its upper end a more 

 or less acute and sometimes recurved point. 

 Tliree or four species in the tertiary for- 

 mations. 

 Genus 23. Thuytes. Branches as in thuja; fruit un- 

 known. 



Several species in oolite. 

 Dovhtful ConifercB. 

 Genus 24. BrackyphyUum. Branches pinnated, disposed 

 on the same plane without regularity; leaves 

 very short, conical, almost like tubercles, 

 arranged spirally. 

 One species in the lower oolite. 



Genus 25. Splienophyllum, Branches deeply furrowed 

 leaves verticillate, wedge-shaped with diclio- 

 tomous veins. 

 Eight species in the coal formation. 



CYCADEjE. 



Leaves only Jmown, 



Genus 26. Cyeadites. Leaves pinnated, leaflets linear, 

 entire, adhering by their whole base, having 

 a single thick midrib, no secondary veins. 

 One species in the grey chalk. 

 Genus 27. Zamia. Leaves pinnated, leaflets entire or 

 toothed at the extremity, pointed, some- 

 times enlarged, and encircled as it were at 

 their base, attached only by the midrib, 

 which is often thickened; veins fine, equal, 

 all parallel, or scarcely diverging. 

 Fifteen species in the lias and oolite. 

 G&n\xs 2Z. Pterophyllum, Leaves pinnated; leaflets al- 

 most equally broad each way, inserted by 

 the whole of their base, truncated at the 

 summit; veins fine, equal, simple, but little 

 marked, all parallel. 



Three species in the variegated marie of 

 the lias; tln:ee species in the sandstone of 

 the lias; one species in the quader sandstcin; 

 one species in the lower oolitic beds. 

 Genus 29. Nilsonia. Leaves pinnated; leaflets approxi- 

 mated, oblong,more or less clongated,rounded 

 at the summit, adhering to the rachis by tlie 

 whole of their base, with parallel veins, some 

 of which are much more strongly marked 

 than others. 

 Two species in the sandstone of the lias. 

 Stems only known. 

 Genus 30. Cycadesdets, Buckland (Mantellia, Brong.) 

 Stem roundish or oblong, covered with 

 densely imbricated scales, which are scored 

 at their apex. 

 Two species in the Portland stone. 



DICOTYLEDONOUS PLANTS OF DOUBTFUL AFFINITY. 



Genus 31. Phylhtlieca. Stem simple, straight, articu- 

 lated, surrounded at equal distances by 

 sheaths, having long linear leaves, which have 

 no distinct midrib. 



One species in the coal formation. 

 Genus 32. Annuluria. (Bornia, Sternberg.) Stem slen- 

 der, articulated, with opposite branches 

 springing from above its leaves; leaves ver- 

 ticillate, flat, usually obtuse, with a single 

 midrib united at the base, of unequal length. 

 Six or seven species in the coal formation. 

 Genus 33. Asterophyllites. (Bornia and Bruckmannia 

 Sternberg,) Stem scarcely tumid at the 

 articulations, branched; leaves verticillate, 

 linear, acute, with a single midrib, quite dis- 

 tinct at the base; fruit, a one-seeded ovate, 

 compressed, nucule, bordered by a mem- 

 branous wing, and emarginate at the apex. 



Twelve species in the coal formation; one 

 species in the transition beds. 

 This is probably an extremely heterogeneous assem- 

 blage, comprehending nearly all fossils, with narrow 

 veinless verticillate leaves that are not united in a cup 

 at their base. 



Genus 34. Bacldra. Stem branched, jointed, tumid at 

 the articulations, deeply and widely furrow 

 ed; leaves verticillate, very narrow, acute, 

 ribless. 



One species in the coal formation. 



