610 REVISION OF ARAUCARIOXYLON KNOWLTON. 



5. Dadoxylon ambiguum Endl. 



Endlicher, Syn. Conif., p. 299. 



Pinites ambiguus Witham Intern. Struct., p. 73, PL ix, figs. 7, 8 ; x, figs. 7-9. 

 Araucarites ambiguus Gopp. in Tchichatcheft* Voyage dans 1' Altai, p. 389. 

 Dadoxylon Unger in Kochlin-Schlumb. etSchimp., Terr, de trans, des Vosges, p. 

 343, PI. xxx, figs A, 1-4. 

 Concentric circles evident ; the medullary rays in transverse section 

 appear numerous and large ; tracheitis provitieti with two to three, or 

 rarely four, rows of contiguous hexagonal pores; medullary rays com- 

 posed of two or rarely three layers of superimposed cells. (Unger.) 



Carboniferous formation, Gateshead, England, and Grauwacke, 

 Niederburbach. 



6. Dadoxylon angustum Felix Sp. 



Araucarioxylon angustum Felix. Stud, fiber Foss. Holzer. Inaug. Diss. Leipzig, 

 1882, p. 81. 



Annual rings plain ; tracheitis provided with one or two rows of small 

 pores on the radial walls; medullary rays moderately high, composed 

 of small narrow cells. (Felix.) 



Carboniferous formation, Lake Illawarra, south of Sidney, ISTew 



South Wales. 



7. Dadoxylon annulatum Dn. 



Dawson, Can. Nat., 1863, Vol. vm, p. 433; Quart. Jour. Geol. Soc. Lond., Vol. 

 xxn, p. 146, PL v, figs. 10-13. 

 Wood cells with two or three rows of hexagonal disks ; medullary 

 rays of twenty or more cells superimposed, in two series ; wood divided 

 into distinct concentric circles, alternating with layers of structureless 

 coal, representing cellular tissue or very dense wood. (Dawson.) 

 Middle coal-measures, Joggins. 



8. Dadoxylon antiquum Witham Sp. 



Pitus ahtiqua Witham, Intern. Struct., 1833, p. 71, Pis. in, IV, figs. 1-7; vn, figs. 



9-12 ; vm, figs. 1-3 ; xvi, figs. 9-10. 

 Pissadendron antiquum Unger, Chlor. Prot., p. 29 ; Goppert Monog. d. Foss. 



Conif., p. 230, PL xxxvm, figs. 3-6. 



Concentric circles usually indistinct; tracheitis rather thick, the 

 radial walls reticulated with two or three series of roundish areoles, 

 which are separated from each other; medullary rays composite, con- 

 sisting or four or five series of superimposed cells. (Goppert.) 



Carboniferous formation, Lennel Braes and Tweed Mill, Berwick- 

 shire, Euglanti. 



9. Dadoxylon medullare Endl. 



Endlicher, Syn. Conif., p. 298. 



Pinites medullaris Witham, Trans. Nat. Hist. Soc, Northumb., etc., Vol, i, 



p. 297 ; PL xxv, figs. 3-8 ; Intern. Struct., 1833, p. 72, PL vi, figs. 5-8 ; vn, 



figs. 7, 8. 



Concentric circles obsolete; tracheitis provitieti with two to four 

 series of contiguous areolae ; medullary rays of two to four series of 

 superimposed cells. (Witham.) 



