450 Scientific Proceedings, Royal Dublin Society. 



T.S. — Eays irregular in size, acute, and gradually tapering ; 30-40 in 

 2 mm. field. Total width of rays in 2 mm. = 0-30-0-40 mm. Average 

 height = 0-52 mm., rising to 0-92 mm. Width about. 0-03-0-04 mm. 1-, 2-, 3-, 

 4-ply. Margin 1-5 cells deep, usually empty. Middle cells thick-walled, 

 often with contents. — fibres with conspicuous septa. 



R.S. — Marginal cells of rays rectangular, square or oblong. In latter case 



often vertical. 



5. Carapa sp. 



No. 83 from commercial source, labelled " Demerara mahogany." 

 PI. XXIV, figs. 16, 17, and 18. 



No. 216 from commercial source, labelled "Demerara mahogany." 



Warm brown, with irregular dark and light streaks and zones, lustrous, 

 roey. Hard, polishes on end grain. Vessels indistinctly zoned, avoiding 

 dark zones. Parenchymatous laminae fine, inconspicuous, irregularly spaced ; 

 occasionally thick, and breaking up into a number of fine ones. Sp. gr. = 

 0-80-0-66. 



C.S. — Vessels isolated or in small groups of 2-5. M. T. D. = 0-25 mm. 

 6-14 groups in 2-mm. field, often with dark contents. — Fibres thick- walled. — 

 Parenchyma circumvasal distinct by reason of dark contents, 1 cell thick ; 

 laminar parenchyma empty, inconspicuous, rare ; 1-4 cells thick. — Eays 

 conspicuous, often with dark contents. 



T.S. — Eays irregular in size and arrangement, tapering gradually ; about 

 30 or 35 in 2-mm. field. Total width in 2 mm. = - 36 mm. -0-42 mm. Average 

 height = 0-75 (1-30-0-07) mm., 4-60 cells. Width = 0'05 (0-02-0-08) 1-, 2-, 3-, 

 4-ply. — Marginal cells triangular; middle cells small, often with dark 

 contents. — Isolated wood parenchyma fibres often adjoining rays. Fibres 

 with frequent and often conspicuous septa, 1-6 between rays. 



U.S. — Marginal cells of rays square or vertically oblong, with rounded 

 lumina ; middle cells horizontal. 



Note. — Possibly this wood and the previous one correspond to " Lowland " 

 and " Highland Crabwood." Stone and, Freeman (17) regard these two 

 as varieties of the same species. 



6. Protium altissimum. 



No. 164, from Botanic Gardens, Georgetown, Demerara, labelled " Cedar 

 {Protium altissimum, Marsh)." PI. XXV., figs. 19, 20, 21. 



Warm brown, lustrous, roey ; vessels indistinctly zoned, often with black 

 glistening contents, scattered or in small groups. Parenchymatous laminae 



