538 Holden . — Jurassic Coniferous Woods from Yorkshire . 
in the Mesozoic. In the formation of traumatic resin canals, it resembles 
Brachyoxylon (6), Paracedroxylon (10), Araucariopitys (8), and A rancario- 
xylon Lindleii (1). Its resemblance to Araucariopitys is indeed very close, 
since, in addition to wound resin canals, both have heavily pitted rays. 
Araucariopitys , however, lacks the wood parenchyma of this specimen, and 
also contains sclerotic diaphragms in the pith. With some of Lignier’s 
specimens, also, it has much in common, but those, like Araucariopitys , have 
sclerites in the pith. Araucarioxylon Lindleii seems to be the nearest, but 
differs in that Professor Seward’s specimen has exclusively terminal wood 
parenchyma. To denote an Araucarian Cedroxylon Mr. Sinnott founded 
the genus Paracedroxylon . Since this wood bears almost the same relation 
to Cupressinoxylon as his to Cedroxylon , it is proposed to call this type Para- 
cupressinoxylon. To emphasize the fact that this wood differs from most 
Cupressinoxyla in the possession of thick-walled heavily pitted rays, such as 
occur in the cedars, it may be called P aracupressinoxylon cedroides. 
Paracupressinoxylon cupressoides (Figs. 15 and 16). 
The sections photographed for Figs. 1 5 and 16 are also from Mr. Lomax. 
This wood has Brachyoxylon tracheary pitting, with no cellulose bars 
of Sanio, thin-walled highly resinous rays, and abundant wood parenchyma 
scattered throughout the year’s growth. Though its wound reaction is 
unknown, it is evident that it belongs to the genus Paracupressinoxylon . 
Since it differs from the last-described wood in the possession of thin and 
unpitted, rather than thick and pitted rays, it may be called Paracupressino- 
xylon cupressoides. 
Metacedroxylon araucarioides (PI. XL, Figs. 17-21). 
This type of wood seems to be comparatively abundant in the Jurassic 
of Yorkshire, Mr. Lomax having sent several specimens, and the writer 
having procured a considerable amount of lignite of this variety from the 
Oolite of both Whitby and Scarborough, and some petrified material from 
the Lias of Robin Hood’s Bay. The sections used for Figs. 17 and 18 are 
from Mr. Lomax, and have already been figured by Professor Jeffrey (7). 
There is a great deal of variety in the pitting of the tracheides. When 
uniserial the pits are often widely scattered and circular in outline, but 
equally often they are compressed and flattened. When more than one row 
occurs in a tracheide, they are at times typically Araucarian — alternate and 
angular, while at others they are in distinctly opposite pairs, or in groups 
of three or four (Fig. 17). It is often noticeable that the pits, however 
Araucarian in arrangement, are not so in outline, — the close approximation 
and consequent compression are absent, and instead, the pits are free and 
circular. The ray structure is shown in Fig. 18. It is obvious that the ray 
