OF THE FOSSIL PLANTS OF THE COAL-MEASURES. 
473 
PLATE 31. 
Fig. 14. Form of vascular tissue. Enlarged 267 diameters. 
PLATE 30. 
Fig. 15. Transverse section of a small organism from Halifax. Enlarged 214 dia¬ 
meters. Mr. Spencer. 
Psaronius RenauItii. 
Fig. 16. Transverse section of a portion of an arborescent stem. Enlarged 2l> dia¬ 
meters. a, ct. Fibro-vascular bundles. b. Phloem layer investing each 
bundle, c. Small gum-canals. Mr. Wild. 
PLATE 31. 
Zygosporites. 
Fig. 17. Sporangium from Halifax containing Zygosporites. Enlarged 110 diameters. 
PLATE 32. 
Fig. 18. Portion of fig. 17. Enlarged 290 diameters. 
PLATE 33. 
Calamites. 
Fig. 19. Transverse section of a young Calamite from the Gannister bed at Moor- 
side, Ashton-under-Lyne. Enlarged 20 diameters, a. Innermost cortex. 
b. Hypodermal zone of prosenchymatous vertical bundles, c. Epidermal (?) 
layer, d. Vascular wedges of the exogenous zone. e. Fistular medullary 
cavity. Mr. W ild. 
Lepidodendron and Halonia. 
Fig. 20. Portion of a transverse section of the medulla and vascular medullary sheath 
of a Lepidodendron. Enlarged 190 diameters, a. Vessels of the medullary 
sheath. b. Older medullary cells. c. Septa of newly-forming cells. 
Mr. Norman. 
