238 Koyal Society, London. 



The anatomy of the axis of tlie cone agrees closely with tliat 

 of tlie peduncle above described, except for the absence of any 

 secondary tissues. The wood has twelve prominent angles, at 

 which the spiral tracheae are situated, so its development was, no 

 doubt, centripetal. The inner tracheae have pitted walls, and are 

 intermixed with scattered parenchymatös cells, imperfectly preserved. 

 The phoem has entirely pereshed. 



The most interesting anatomical feature is the course of the 

 leaftrace bundles, which can be followed with the greatest exactness 

 ,-on comparing sections in the three direclions. 



A single vascular bündle Starts from each angle of the stele 

 for each sporophyll, and passes obliquely upwards. When less 

 than half way through the cortex, the trace divides into three 

 bundles, one median and two lateral. The lateral Strands are not 

 always both given off exactly at the same point. A little further 

 out, the median bündle divides into two, which in this case lie in 

 the same radial plane, so that one is anterior, and the other 

 posterior. The median posterior bündle is the larger, and before 

 leaving the cortex this, in its turn, divides into three. There are 

 now six branches of the original leaftrace, three anterior, and 

 three posterior, which respectively supply the lower and upper 

 lobes of the sporophyll. The three segments of the lower lobe 

 are supplied by the two lateral bundles flrst given off, and by the 

 anterior median bündle, while the upper segments receive the 

 posterior median bündle and its two lateral branches. In the base 

 of the sporophyll, all six bundles can be clearly seen, in tangential 

 section, three above and three below. As the segments become 

 free, one bündle passes into each, and runs right through the 

 pedicel to the lamina. In the fertile lamina the bündle subdivides, 

 a branch diverging to the base of each sporangium. 



One of the longitudinal sections passes through the base of 

 the cone, so as to show part of the peduncle in connection with 

 it. In this peduncle secondary wood is present, just as in the 

 separate specimen belonging to the Willi am so n collection. 

 Higher up in the axis of the cone, where the sporophylls begin to 

 appear, the secondary wood dies out. This evidence materially 

 confirms the conclusion that the Williamson peduncle really 

 belongs to our strobilus. 



Diagnosis. 



It is evidently necessary to establish a new genus for the 

 reception of this fossil; the generic name which 1 propose is 

 Cheirostrobus, intended to suggest the palmate division of the 

 sporophyll lobes (xeiß, hand). The species may be appropriately 

 named Pettycurensis, from the locality where the important deposit 

 occurs, which has yielded this strobilus, and so many other valuable 

 specimens of palaeozoic Vegetation. The diagnosis may provisionally 

 run as follows : 



