DixoN-^-Mahogany, Recognition of some Different Kinds. 455 



each group. M.T.D. = 026 mm. 12-20 in 2 mm. field. Occasional tyloses,- — 

 Fibres thick-walled and regular. — Circumvasal parenchyma often filling up 

 spaces between individual vessels ; laminae 1-4 cells thick, discontinuous, 

 anastomosing, and splitting, often with contents. Eays distinct, with contents. 



T.S. — Eays irregular in height and arrangement, about 110-150 in 2-mm. 

 field. Total width in 2-mm. = 0-26 mm. Height = 0'20 mm (0-02-0-56 mm.). 

 1-18 cells. Width 0-01-0-02 mm. 1-2 ply. Margin distinct. Eays with 

 occasional contents. — Fibres non-septate ; 2-5 between rays. 



U.S. —Marginal cells not always vertically elongated, sometimes rhomboid, 

 often with thick, pitted walls. 



Note. — The rows of vessels in echelon suggest that this wood is derived 

 from one of the Sapotaceae or Guttiferae. Possibly it is from a species of 

 Calophyllum. 



14. Cedrana. 



No. 234 from commercial source, marked " Cedrana from Para." PI. XXIX., 

 figs. 43, 44, 45. 



Light rose-brown, almost flesh-coloured, lustrous and roey, with occasional 

 dark zones. Close interrupted parenchymatous laminae connecting vessels 

 tangentially about 0-3-0 - 5 mm. apart. Sp. gr. = - 57. 



C.S. — Vessels slightly compressed, isolated, occasionally in pairs. M.T.D. = 

 0-38 mm. 3-6 in 1-mm. field. Tyloses (not lignified) frequent, forming a 

 lining to vessels, and not extending to middle.— Fibres thin-walled. 4-18 

 between rays. — Circumvasal parenchyma narrow, distinct, with dark contents ; 

 laminar in short tangential plates extending laterally from vessels 1-10 cells 

 thick, often appearing to connect adjacent vessels tangentially. — Eays distinct, 

 fairly dark. 



T.S. —Eays irregular in size and arrangement. Thick, 3-5-ply and thin, 

 1-ply. About 12 thick and 37 thin rays in 2-mm. field. Total width in 

 2 mm. = 0-34 mm. Height of 3-5-ply rays = 0'3()-O'7O-l-50 mm. 8-50 cells. 

 Width = 0-60 mm. 3-, 4-, 5-ply. Height of 1-ply rays = 0-10 mm. - 0-08 mm. 

 1-13 cells. Width of 1 -2-ply rays = 0-04-006-0-08 mm. 



T.S. — Margin of 3-5-ply rays distinct, often many cells deep and "rat- 

 tailed." Contents small, parietal. 



U.S. — Marginal cells square or oblong, vertical or horizontal. 



15. Panama Mahogany. 

 No. 232 from commercial source. PI. XXIX., figs. 46, 47, 48. 



Yellow ochre, lustrous with shaded brown streaks, indistinct zones. 

 Eoey. Vessels scattered, surrounded with yellow margin which is deepest in 



gCIENT. PROC. E.D.S., VOL. S.V., NO. XXXIV. 4c 



