616 REVISION OF ARAUCARIOXYLON KNOWLTON. 



7. Araucarioxylon Heerii Beust. 



Beust, Untersuch. ii. Foss. Holzer aus Gronland. Neue Denkscbriften d. allg. 

 Schw. Gesellscb. f. d. gesamint-Naturwiss., Vol. xxix, 1884, p. 16, PI. i, u, 

 in, fig. 9. 



Concentric circles less distinct, 2 to 3 mm broad, both exterior and 

 interior zones composed of thick-walled cells, which are rectangular, 

 oval, or rarely hexagonal in transverse section ; pores large, hexagonal, 

 in one to two or rarely three contiguous series ; medullary rays numer- 

 ous, simple or compound, composed of one to eighty-two superimposed 

 cells, of which one, rarely two or very rarely three, come opposite to a 

 single tracbeid ; resin ducts none. 



Habitat. — Stauekerdluk, Greenland. 



8. Araucarioxylon Schmidianum Schleiden Sp. 



Felix, Studien u. Foss. Holzer. Inaug-Diss. Univ. Leipzig ; Leipzig, 1882, p. 62. 

 Pence Schmidiana Schleiden, ueber d. Nat. d. Kieselbolzer ; Jena, 1855, p. 36. 

 Cedroxylon Schmidiana Kraus in Scbimp., Pal. Veg., n, p, 373. 



Annual circles evident or sometimes indistinct; tracheids provided 

 with a single row of large contiguous pores ; medullary rays two to 

 fifty-five cells high, one to three cells broad. 



Habitat. — Tiruvicary and Pattacary, near Pondicherry, India. 



9. Araucarioxylon Robertianum Scbenk. 

 Engler's Bot. Jabrb., Bd. in, 1882, p. 355. 



Annual rings sharply separated by the presence of two or three 

 layers of tangentially compressed tracheids in the fall-wood ; summer- 

 wood passing gradually into the fall-wood ; walls of the tracheids pro- 

 vided with one to four rows of spirally placed pores, which are irregu- 

 larly compressed or hexagonal ; medullary rays numerous, in a single 

 row or in the middle, rarely in two rows of cells, which range in num- 

 ber from one or two to twenty-four, or rarely as many as forty-two to 

 forty-four. 



Habitat. — Assanole, near Eanigaudsch, India. 



10. Araucarioxylon latiporosum Kraus. 



Scbimp. Pal. Veg., n, p. 384. 



Pinites latiporosus Cramer in Heer's Flor. Foss. Arct., Vol. I, 1868, p. 176, PI. lx, 



figs. 1-8. 



Annual rings distinct, 3.48 to 6.1 mm broad; wood-cells 1.9 to 2.7 mm 

 long, 20 to 90.3 micro-millimeters thick, 46.6 to 80,u broad, provided with 

 a single row of large contiguous pores, which have an outer average 

 diameter of 35 by 17 micro-millimeters and an inner diameter of from 

 8.4 by 3 to 6 micro-millimeters ; average number of pores to each 

 wood-cell ten to thirteen, sometimes as many as forty; medullary rays 

 composed of a single series of four to seventeen superimposed cells, the 



