OF THE FOSSIL PLANTS OF THE COAL-MEASTJEES. 
701 
Bachiopteris Oldhamia. 
Plate LIII. fig. 20. Transverse section of a matured petiole, magnified 32 diameters. 
„ fig. 21. Transverse section of the upper part of a petiole, magnified 32 
diameters. 
,, fig. 22. Transverse section of upper part of a petiole, with the gutter- 
shaped vascular bundle, magnified 32 diameters. 
„ fig. 23. Transverse section of a petiole near its extremity, with the vas- 
cular bundle cylindrical, magnified 32 diameters. 
„ fig. 24. Transverse section of the extremity of a petiole, magnified 32 
diameters. 
Plate LIV. fig. 25. Longitudinal section of a petiole like fig. 20, magnified 65 dia- 
meters. 
Plate LIII. fig. 25 A. Transverse section of a petiole, with a cluster of small vessels at 
one side, preparing to become detached as two secondary bundles, 
magnified 32 diameters. 
„ fig. 25 B. Transverse section of a petiole like fig. 20, giving off trifid vas- 
cular bundles to secondary rachis, magnified 32 diameters. 
Plate LIV. fig. 26. Transverse section of a smaller petiole giving off trifid secondary 
vascular bundles, magnified 32 diameters. 
,, fig. 27. Longitudinal section of a petiole giving off a large secondary 
rachis, magnified 32 diameters. 
Bachiopteris duplex. 
Plate LY. fig. 28. Transverse section of a petiole, magnified 8 diameters. 
Plate LIV. fig. 29. Longitudinal section made through the longer axis of fig. 28, 
magnified 8 diameters. 
„ fig. 30. Vascular bundles of a matured petiole disturbed by pressure, but 
with the crescentic bundle {a!) separating from the extremity of 
the “ hour-glass ” bundle, magnified 24 diameters. 
„ fig. 31. Reticulated , vessel of the “hour-glass” bundle, enlarged 280 
diameters. 
„ fig. 32. Another modified form of fig. 31, magnified 280 diameters. 
,, fig. 33. Small semireticulated vessel from the surface (a", fig. 30) of the 
“ hour-glass ” bundle, magnified 280 diameters. 
„ fig. 34. Barred vessel from the cortical side of the canal ( a ", fig. 30), mag- 
nified 280 diameters. 
Plate LV. fig. 35. Vascular bundle of a matured petiole, the crescentic one sub- 
dividing into two secondary ones ( a a'), magnified 20 diameters. 
„ fig. 35 A. Part of a transverse section of a primary petiole, giving off two 
bundles ( aa , aa) to two secondary petioles, one of wdiich in turn 
is giving off the ternary bundle ( x ), enlarged 5 diameters. 
5 B 2 
