318 Proceedings of the Royal Society of Victoria. 



formed by the anastomosing nerves. The mid-rib is broad and 

 distinctly hollowed. 



It is interesting to note the occurrence of this species in the 

 Bowen River Coal Field of Queensland, since its previous records 

 seem to have been only from the upper coal measures of 

 Bowenfels in New South Wales. 



Locality and Horizon. — Baron River (below coal seams), 

 Queensland. Carbo-permian (Bowen River Coal Fields). [2160]. 



CONIFERAE. 



Araucarioxylon, Kraus, 1864.' 



General Remarks ofi the Determination of J^ossil Coniferous 

 Wood. — The generic name Araucarioxylon is here employed in a 

 restricted sense for coniferous wood allied to Araucaria and 

 Dammara, and agrees in tlie main with Kraus' definition, in 

 having the medullary rays in a single row .on the tangential 

 section, with bordered pits mutually in contact.- The determina- 

 tion of generic or typical groups in the Coniferae from a 

 microscopical examination of their fossil woods is a somewhat 

 hopeless task, notwithstanding the beautiful preservation of the 

 tissues in many silicitied and otherwise mineralized specimens. 

 Although the wood thus mineralized often shows a structure so 

 well replaced that thin sections of it can be examined in all their 

 details, under a high magnitication, with that of a recent wood ; 

 yet, as some eminent palaeobotanists, as Solms-Laubach,'^ Scott,* 

 and others, have recently pointed out, unless we can examine 

 sections taken from all parts of the stem and root, and sliced in 

 the various directions necessary to give a complete knowledge of 

 their structure, we may easily fall into the error of confusing 

 the woods of entirely different groups. The above genus affords 

 a case in point, in which the stems of Cordaites were grouped 



1 O. Kraus. — " Mikroskopische Untersuehunjjen iiber den Ban lebender uiid vor- 

 weltlicher Nadelhijlzer." Wurzburjrer Naturwiss. Zeitschr, vol. .'i (1864). 



See also Schiniper, 1870, Traite, Pal. V^g., vol ii., pt. 1, p. ;580. 



2 The arraiigeineiits and characters of the bordered pits of the tracheides are, however, 

 •0 inconstant, even in the Araucarian ^roup, that little value can be attached to them for 

 determinative purposes. 



3 " Fossil Botany," Cambridge, 1891, pp. 80-82. 



4 " Studies in Fossil Botany," London, 1900, p. 419. 



