366 ME. ARTHUR JOHN MASLEN ON THE 



Structures outside the Aoris. — Unfortunately, in the sections of this form the structures 

 outside the central axis of the cone are not well preserved. In the longitudinal sections 

 the pedicels of the sporophylls are seen radiating out from the axis with a slight upward 

 direction, and in the transverse section shown on PL XXXVI. fig. 1 sections of the 

 sporophylls, sph., are shown attached to the sporangia, sm. 



Of the spores hut little can be said. They are found singly and in tetrads. There 

 is no evidence to prove whether the cone was homosporous or heterosporous, the only 

 spores seen being from "02 to *03 millim. in length, which is about the usual size of 

 the spores which are described among Lepidostrohi as microspores. No trace of the 

 ligule can be seen in these slides, probably owing to the imperfect preservation of the 

 outer portions of the strobilus. 



On PI. XXXVII. fig. 16 is shown a transverse section of one of the larger laminae 

 seen around the periphery in both the transverse sections (C.N. 1613 d, S. 85). A 

 somewhat similar lamina is also shown at the periphery of the transverse section, 

 PL XXXVI. fig. 1. As can be seen by a comparison of the sporophylls shown in these 

 two figures, the pedicel, when traced from the axis outward, exhibits a progressive 

 enlargement of its lateral wings, and when quite free from the sporangium (fig. 16) 

 the lamina becomes of considerable size. In fig. 16 the vascular bundle is seen at l.t., 

 illustrating tlie typical uninervate character of the genus, while below it is a somewhat 

 irregular space. The main tissue of the sporophyll is a thin-walled, small-celled 

 parenchyma, passing at the periphery and at the edges of the leaf into a thicker- walled 

 protective zone. 



PL XXXVIT. fig. 17 is a section of the thin edge of a lamina quite similar to that 

 shown in fig. 16 ; it exhibits cells having an appearance somewhat similar to those of 

 the outer cortex of the axis, and bounded by a distinct epidermis, e. 



On PL XXXVII. fig. 18 is an enlarged drawing of the vascular bundle shown at l.t. 

 in fig. 16. The xylem is seen at x. and the phloem aty., with isolated barred cells at s.t. 

 The bundle appears distinctly collateral. 



PL XXX VII. fig. 19 is the transverse section of two smaller scales from the periphery 

 of the same section. Doubtless they belong to sporophylls inserted lower down on 

 the axis. The outside of the cone was well protected by these overlapping free 

 portions of the sporophylls, which doubtless extended upward for a considerable 

 distance, gradually becoming smaller. 



PL XXXVII. fig. 20 is an enlarged drawing of one of the bundles from fig. 19. Here 

 the xylem, x., appears to be completely surrounded by a thin-wailed tissue (probably 

 phloem), so that as the apex of the sporophyll is approached tlie bundle appears to 

 become concentric instead of collateral. 



LePIDOSTROBUS OLDHAMIUS (|3). 



The general morphology of this form— the form originally described by Williamson as 

 L. oldhamius *, which for convenience I propose to designate my /3 type— has been 

 already described in the introduction. The sections to be specially considered now 



* " Organizafcion," Part XIX. p. 28. 



