190 ON THE STRUCTURE AND AFFINITIES OF METACLEPSYDROPSIS DUPLEX. 
Puate IV. 
Metaclepsydropsis duplex. 
Fig, 39. Transverse section of petiole-trace above level of Pl. ILI. fig. 38. g=groove ; pin. tr=pinna- 
trace ; aph. tr =aphlebia-trace. Slide 1243. x19. 
Fig. 40. Transverse section petiole to show the various traces departing from it. pet. tr=petiole- — 
trace ; pin. tv = pinna-traces ; aph. tr =aphlebia-traces. Kidston Collection, 1314. x 32 
Fig. 41, Transverse section of normal primary pinna-trace. The shape is like a horse-shoe with ends 
ineurved. Slide 1261. x 40. 
Fig. 42. Transverse section of an abnormal secondary pinna-trace with tertiary pinna-trace departigg 
from it. Both traces are closed rings. Slide 1258. x 40. 
Fig, 43. Transverse section of abnormal primary pinna-trace. The trace is a closed ring of xylem. 
Slide 1168. x 40. 
Fig. 44. Transverse section of root-trace showing that it is diarch. pra=protoxylem group, Slide ~ 
POU xis:- 
Fig. 45. Transverse section of stem to show inner tracheides and parenchyma. «!=outer xylem; 
«x? =inner zone; p=conjunctive parenchyma. Slide 1109. x 36. 
Fig, 46. Transverse section of branch resembling Botrychioxylon. In places the xylem shows a perfect 
radial arrangement. Slide 1233. x 18. ~— 
Fig. 47. Transverse section of stem with petiole-trace attached. The stem has a central zone almost 
entirely composed of parenchyma ; only one tracheide can be seen, The petiole-trace is much distorted. 
= parenchyma in the stem ; ¢=tracheide. Slide 1207. x15. 
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