544 Holden. — Jurassic Coniferous Woods from Yorkshire , 
cladoxylon in which the ‘ Eiporen ’ persist, is doubtful. There are many 
features in which the Araucarians and Podocarps are alike, but it still 
seems unlikely that it is from forms like Phyllocladus that the Araucarians 
have been derived. It seems more probable that large e Eiporen ’ are in the 
nature of sports, 'without diagnostic significance. Their occurrence in forms 
as widely separated phylogenetically as Pinns , Sciadopitys, and Phyllocladus 
indicates such to be the case. 
Summary. 
1. There were present in the Jurassic of Yorkshire a few typically 
Abietineous woods, a few typically Araucarian, and a large number 
intermediate between the two. 
2. The character of these transitional woods corroborates other evi- 
dence — both palaeobotanical and comparative anatomical — pointing to the 
conclusion that the Abietineae are the oldest Conifers, and ancestral to the 
Araucarineae. 
3. Comparative examination of living and fossil forms leads to the 
rejection of all criteria except cellulose bars of Sanio as an infallible test for 
tribal affinities. That these bars are of real diagnostic significance, and not 
simply incidental to the spacing of the pits, is indicated by their absence in 
the seedling stem of Araucaria and Agathis, where the pits are as remote 
as in Pinus , and their presence in Protobrachyoxylon , where the pits are as 
crowded as in Araucaria or Cordaites . 
In conclusion, I wish to express my thanks to Professor Jeffrey for 
material and advice in connexion with this investigation. 
Literature cited. 
1. Seward, A. C. : Catalogue of Mesozoic Plants, British Museum, Jurassic Flora, Part 2, 1904, 
pp. 56, 57, Pis. VI, VII. London. 
2. Gothan, W. : Die fossilen Holzer von Konig Karls-Land. Kung. Svensk. Vetenskap. Hand- 
lingar, xlii, No. 10. 
3. : Di e fossilen Holzreste von Spitzbergen. Kung. Svensk. Vetenskap. Hand- 
lingar, xlv, No. 8. 
4 . Lignier, O. : Veg^taux fossiles de Normandie, II and IV (i re Serie). Caen, 1907. 
5 . Kraus, G. : in Schimper’s Traite de Paleontologie veg^tale, v, pp. 363-85. 
6. Jeffrey, E. C., and Hollick, A. : Cretaceous Coniferous Remains, Staten Island. Mem. New 
York Bot. Garden, iii, PI. XXI. 
: The Araucarioxylon Type. Proc. Am. Acad. Arts and Sciences, xlviii, No. 13, 
Nov. 1912. 
7 . 
