2 Transactions of the Society. 



support, and this in the sterile tissue at the base spread out into a 

 cup of short tracheids, which approached the bases of the sporangia. 

 The whole was of small size, measuring only * 5 mm. in diameter, 

 and * 8 mm. in height. 



The Receptacle. — The central axis of the synangium and its 

 base are composed of normal elongated parenchymatous cells. 



In the base of the fructification these cells are short, and contain, 

 all round the margin, a cup of short tracheids, which are spirally 

 thickened. 



These are typical leaf-tracheids, and they are seen to end 

 immediately under the bases of the sporangia; they evidently 

 served to supply the sporangia during development. 



I have been able to find no vascular tissue in the part of the 

 receptacle between the sporangia, and I think it very improbable 

 that there was any. 



The columella was hollowed out into a cup for a distance of 

 about one-third of its length from the top, and into this cup it 

 seems most likely that dehiscence took place. 



The columella in transverse section is seen to fit closely up to 

 the sporangia, and was provided with ridges to fit in between them. 



The base of the synangium seems to have contracted, although 

 this might conceivably be due to the obliqueness of the longitudinal 

 sections. Its base is ragged, and seems to have been torn from its 

 support. 



Of the structure of the tissue surrounding the whole synangium, 

 nothing can be made out, except that it was probably composed of 

 two or three layers of elongated cells. 



Sporangia and Spores. — The sporangia are all provided with 

 separate walls, which, as preserved, appear as one black line. 



They are about ■ 2 mm. in diameter in a transverse section, 

 and are about " 7 mm. long. 



In two specimens they contain spores. These spores are oval, 

 and have no ornamentation. Their wall is preserved as a single 

 membrane. They measure about 15 fi by 12*5 /x. 



Similar spores occur scattered in the matrix of the section. 



EXPLANATION OF PLATES II. AND III. 



Pig. 3. — Transverse section through the top, showing the cup at the top of the 



columella, sporangia, and spores. X 100. 

 „ 4. — Longitudinal section, slightly oblique, showing cup at summit of 



columella, x 48. 

 „ 5. — Longitudinal section, showing character of columella. X 48. 

 ,, 6.— Base of Pig. 5, enlarged, showing cup of tracheids in section, x 100 



(about). 

 „ 7. — Longitudinal section of base, showing cup of tracheids cut tangentially 



so as to give a partial surface view, x 100. 



Figs. 1 to 5, and 7, are from photographs by Mr. W. Tarns, of Cambridge. 

 Fig. 6 is from a camera-lucida drawing by the author. 



