FIG. 494. A, Stephanospermum akenioides; s, space between integument and 

 nucellus ; n, nucellus ; e, inner part of testa ; sc, sclerotesta ; t, t, tracheidal 

 mantle ; pc, pollen-chamber ; a, archegonia ; td, tracheidal pad. B D, Cono- 

 stoma oblongum; a, level of the transverse section shown in fig. C; 6, level 

 of transverse section D; m, lobes of tissue surrounding the micropyle; 

 sa, sarcotesta; v, vascular bundles; p, plinth. B', section of lagenostome 

 and part of the integument; /,/', flanges; I', wall of micropyle-funnel. 

 E, F, G, Gnetopsis elliptica; t, tent-pole. F, section of the plumes. 

 G, section through the lagenostome. H, Gnetopsis from Barnsley, York- 

 shire, slightly enlarged. I, Physostoma elegans; h. hairs. K, L, Mitro- 

 spermum compression ; cf, inner flesh ; n, nucellus and megaspore. L, trans- 

 verse section. M, microspores and (?) male gametes of Physostoma elegans. 

 N, microspore of Physostoma showing part of exine and the internal cells. 

 (A I, N, M, after Oliver; H, Kidston Coll. No. 1255; K, L, after Mrs Arber.) 



