1914] HOLDEN— CRETACEOUS LIGNITES 175 



Summary 



1. An Araucarioxylon from the Raritan Cretaceous of Cliff wood, 

 New Jersey, shows bars of Sanio near the pith of the stem, similar 

 to those on the cone axis of the living Araucarineae. 



2. Brachyoxyla from the same locality are as a rule very similar 

 to those from Kreischerville, Statert Island, differing only in such 

 details as arrangement of medullary sclerites and structure of the 

 bast. 



3. The Cupressinoxyla of Cliff wood all lack cellulose bars of 

 Sanio in the mature wood, and should on that account be placed 

 in the new genus Paracupressinoxylon. 



4. The occurrence of three absolutely typical Pityoxyla, and 

 not a single typical Araucarioxylon, among these lignites seems to 

 indicate that in tracing back the families of living conifers it is the 

 Abietineae which remain unchanged, and the Araucarineae which 

 become less and less like living representatives of that family. The 

 same conclusion may be drawn from a consideration of the lignites 

 of Staten Island. 



5. The variety of structure of these Mesozoic araucarians has its 

 bearing on the question of the monophyletic or diphyletic origin of 

 the Coniferales. There are certain features which have been sup- 

 posed to sharply differentiate the araucarians from the other 

 families. Both fossil and comparative anatomical evidence demon- 

 strate the fallacy of this view. As regards wood structure, even 

 feature of the Abietineae — resin canals, bars of Sanio, thick-walled 

 pitted rays, wood parenchyma (terminal and diffuse), even to as 

 small and unimportant details as fusion pits in the rays and regu- 

 larly alternating bands of hard and soft bast — has been found in 

 the Araucarineae, living or extinct. As regards strobilar anatomy, 

 Eames 7 has shown that the stages in the reduction of the female 

 cone are closely paralleled in various cupressineous and taxodineous 

 genera, and the writer 8 has shown that in one Mesozoic araucarian 

 (Voltzia) there was a double cone scale, like that of the living genus 



7 K ames. Arthur J., The morphology of A gat h is australis. Ann. Botany 27 : 1-38. 

 pis. 1-4. r 9 i 3 . 



•Holdex, Rith. Some fossil plants from eastern I mada. Ann. Botany 

 27:243-255. pis. 22, 2 3. 1913. 



