INDIAIS" JUEASSIC GTMN"OSPEEMS. 



79 



This agreement in structural details in tlie two specimens lends support to the 

 reference of tlie stem to the Williamsonian type, a reference which is further 

 strengthened by its association with fronds of FtilopJiylhim cutchense, or, as Seward 

 prefers to regard them, WilUamsonia pecten. It will he rememhered that fronds of this 

 type are described in actual connection with a similar stem in the ' British Museum 

 Catalogue of Mesozoic Plants* (27, p. 193). 



The stem in block II. (PI. 9. fig. 1; PL 8. figs. 16 & 17) is about 13'6 cms. long and 

 2'5 cms. wide, showing two complete zones of large leaf -scars and part of a third, and 

 three zones of narrow scars. In the alternation of zones of large and small leaf-scars, 

 its external characters agree with those of the Bucklandian type of stem (3). Some of 

 the larger scars in their upper parts show five slight depressions marking the position 

 of the vascular bundles which supplied the leaves (see reistmantcl, 7, p. 78). 

 Lateral compression has occasioned the l)reaking up and displacement of much of the 

 harder tissue, so that in section it is only possible to determine general characters. The 

 pith and cortex are apparently of the usual type for this group, both having secretory 

 sacs. In the cortex are several vascular structures, presumably leaf -trace bundles and 

 irregularly developed periderm. The xylem, though now much broken up owing to 

 conditions of preservation, shows signs of having formed one continuous zone, as appears 

 to be usual in the fossil Cycadophyta (37, p. 74). It is compact with narrow medullary 

 rays, and is clearly endarch (PI. 8. fig. 16). No evidence with regard to the pitting of 

 the elements is obtainable. In general characters this stem agrees with the previously 

 described example, and is thus referred to the same comprehensive type. 



C. IncertsB Sedis. 



On the surface of Block IV. was noted a small rounded structure, which was carefully 

 removed by chipping away a little of the surrounding matrix. The structure is 

 evidently a small bilateral seed 3 mm. long, 3 mm. wide, and 2 mm. in thickness just 

 above the base (PL 7. fig. 9). At the base there is an indication of a pedicel. It is 

 impossible to determine whether the seed is Cycadean or Coniferous. Oldham and Morris 

 (19, pi. 35. fig. 9) figure similar examples and incline (p. 36) to refer tbcm to cycadean 

 affinities, on grounds of association, although, as they point out, " so fiir as the seeds 

 themselves are concerned, they might be coniferous." 



IV. CONCLUSIOX. 



The above investigation of certain gymnospermous types of Liassic ago from the 

 Bajmahal Hills in Bengal adds some facts as regards structural details to the already 

 fairly extensive literature concerning Indian Mesozoic Plants (see references to the 

 works of reistmantcl, 4-9 ; Oldham and Morris, 19). This literature, although dealing 

 mainly with the external morphology of the types plainly indicates the similarity of the 

 Mesozoic Plora of India to floras of the same age in other parts of the world. The 

 geographical and geological distribution of the genera described above are too well 



known from the writings of various authors to render a discussion upon this sulgcct 



2 



