454 Scientific Proceedings, Royal Dublin Society. 



in 2 mm. field, often with tyloses. — Fibres very thick-walled. — Parenchyma 

 circumvasal only, with dark contents. — Bays with contents. Occasional 

 broad rays many cells across. 



T.S.— Kays uniform (except for occasional giant rays), acute, about 100 

 in 2-mm. field. Total width of rays in 2 mm. = - 34 mm. Height = 0'35 mm., 

 width = 0016 mm., 1-, 2-ply. Margin 1-5 cells deep, acute, often with 

 crystals. Middle cells thick-walled, often with contents. Giant rays with 

 bowed sides, many cells across, with dark contents in middle cells, a circular 

 curve or even a space. 



U.S. — Fibres fine, septate. — Marginal cells of rays tall, thick-walled. 



12, Dalli. 



No. 169, from the Botanic Gardens, Georgetown, Demerara, labelled 

 " Dalli." PL XXVIII., figs. 37, 38, 39. 



Pink brown, lustrous, not roey, vessels indistinctly zoned, contents small, 

 dark or dirty white. Dense and light zones of fibres. Parenchymatous 

 laminae absent in 15 mm. Sp. gr. = 0'5. 



C.S.— Vessels circular, scattered or in small radial groups. M.T. D. = 

 - 23 mm. 10-15 groups in 2-mm. field. Contents parietal, dark. — Fibres 

 thin-walled, empty. — Parenchyma circumvasal, narrow, sometimes with 

 parietal contents. — Pays with parietal contents. 



T.S. — Pays irregular in size, acute, sides irregular and sinuous, about 

 15-20 in 2-mm. field. Total width in 2 mm. = - 30 mm. Height = 1T3 mm. 

 (0-67-1-80). Width = 0-050. (1-,) 2-, 3-, 4-, (5-) ply. Margin 1— several 

 cells deep, empty. Middle cells thin- walled, small, with parietal contents. — 

 Parenchyma in short columns, 1 cell across. Cells square. 



U.S. — Fibres conspicuously septate. — Margin of rays of oblong, vertical or 

 horizontal, or of square cells. 



13. Guatemala Mahogany. 

 No. 84, from commercial source, labelled " Guatemala mahogany." 

 PI. XXVI II, figs. 40, 41, 42. 



No. 217, from commercial source, labelled " Guatemala mahogany." 

 No. 60, from commercial source, labelled " Padouk." 



Warm brown, dull, not roey (?), with indistinct dark zones. Hard, 

 polishes on end grain. Vessels indistinctly zoned, forming oblique or sinuous 

 radiating series. Parenchymatous laminae fine, irregular, often interrupted ; 

 about 1 mm. to - 25 mm. apart. Sp. gr. = 0-74-0-62. 



. C.S. — Vessels somewhat tangentially compressed, isolated or in radially 

 oblique or radially sinuous groups, with parenchyma between the vessels of 



