Palaeontologie. 159 



their essential agreement in the primary and secondary wood- 

 structure with Calamopitys Saturni and C. annularis. The 

 author is indebted to Count Solms-Laubach for the 

 opportunity of examining sections of the two latter species. 



II. Pitys Witham, emend. 



1. Pitys antiqua. Sections of several specimens were 

 examined, chiefly in Mr. Kidston's collection, from the 

 Calciferous Sandstones of Lennel Braes, Berwickshire. The 

 results of the investigations are as follows: 



1 . The large pith (22 — 34 mm. or more in diameter in the 

 specimens examined) contains a large number (40 — 50) 

 of small primary xylem-strands, situated near the peri- 

 pher)' of the pith but nsually embedded in its tissue. 



2. The Strands, which are m esarch in structure, occasio- 

 nally anastomose, and, in places, are found passing out 

 through the secondary wood. They no doubt represent 

 the leaf-traces. 



3. The tracheides of the secondary wood have the typical 

 Araucarian or Cordaitean pitting; tangential pits some- 

 times occur. The larger medullary rays are 4 cells 

 or more in thickness, and are much dilated where they 

 join the pith. Strands of xylem-parenchyma also occur, 

 though sparingly. 



2. Pitys Withami (Lindl. <& Hutt. sp.). 



This species, (the Craigleith Tree.) with which P. medullaris 

 Lindl. & Hutt. is united, also shows primary xylem-strands, as 

 in P. antiqua. 



3. P. primaeva Witham. Here also traces of the primary 

 xylem-strands were found, in a lateral branch. 



In the neighbourhood of the branch the medullary rays 

 are found to be enormously dilated, giving rise to a 

 structure closely resembling that of Williamson's 

 Lyginodendron anomalum, from Arran. 



Witham 's genus Pitys is revived, with the limits adopted 

 by Goeppert (Bot. Centralblatt. Bd. V. 1881) and the small 

 primary Strands of xylem are added to the generic characters. 



III. Dadoxylon Spenceri sp. nov. 



This stem, previously described by Williamson (Organi- 

 zation of Fossil Plants of Coal-Measures. Part X. Phil. Trans. 

 R.S.London. 1880. Part II) was found by the late Mr. S p encer 

 at Hebden Bridge, near Halifax. The horizon, though referred 

 by Mr. Spencer to the Yoredale Rocks, is more probably 

 Upper Carboniferous. 



The pith, 5 or b mm. in diameter, is obtusely pentagona!, 

 and from the angles the double leaf-traces pass out, almost 

 horizontally, through the wood. A few small, but distinct, 

 mesarch xylem-strands occur at the inner edge of the wood, 



