50 Oliver and Salisbury —On the Seeds of the Conostoma Grotip. 
Fig. 17. Longitudinal section of lower end of seed, showing testa (t.), and tapetum (tap.) several 
eell layers deep. U. C. L., R. 121 (Shore), x 80. 
Fig. 18. Lagenostome enlarged from specimen given in Fig. 16. Ig.o., outer layer of wall, 
Ig'i; inner layer of wall of lagenostome ; pi., wall of plinth ; pl.j ., plinth jacket ; uf, upper flange, 
l. f, lower flange of lagenostome. U. C. L., R. 1 1 7 (Shore), x 125 (see p. 7). 
Fig. 19. Median section of apex of seed with prothallus (J>r.) ; the asymmetry of the internal 
ribbing of micropyle wall shown, i.r., internal rib ; m.t., micropylar tube ; m.f., micropylar funnel ; 
lg ., lagenostome ; pi., plinth cavity ; Is., tissue of plinth (‘ lens ’) ; p.g., pollen-grain ; t.p., ‘ tent pole ’ ; 
tap., tapetum. U. C. L., R. 125 (Deighton, Yorks.), x 75 (see p. 20). 
Fig. 20. Longitudinal section of micropylar tube (m.t.) and lagenostome; the wall of the 
lagenostome is cut tangentially, the cells showing conspicuous reticulated sculpturing. U. C. L., 
R. 1 15, 1 (Shore), x 182 (see p. 18). 
PLATE III. 
Fig. 21. Transverse section through base of the megaspore cavity, showing the basal wings 
formed by the major ribs (A 1 , A 2 , A’ 3 , A 4 ), three of which have corresponding vascular bundles, 
and the minor ribs (r x , r 1 , r 3 , r 4 ), which have no vascular elements, tap., tapetum ; bl., ‘ blow-off’ 
layer. U. C. L., R. 140 d (Langendreer). x 27 (see p. 29). 
Fig. 22. Transverse section from the same series as above through the middle region. Major 
ribs (A 1 , A 2 , A 3 , A 4 ) ; minor ribs (r l . r 1 , r 3 . r 4 ). U. C. L., R. 140 b (Langendreer). x 27 
(see p. 28). 
Fig. 23. Section from the same series through the apex ; the four minor ribs have died out. The 
four major (A 1 , A 2 , A 3 , A 4 ) are pierced by the canopy loculi (loc.), in which the black dots, seen 
in two, are the vascular bundles, me., micropyle ; bl., ‘ blow-off’. U. C. L., R. 140 a (Langendreer) 
x 27 (see p. 28). 
Fig. 24. Longitudinal section through the same seed as in Fig. 26. Micropyle (me.) showing 
the concave upper edges of the major ribs (A 1 e, R 3 ^). The lagenostome ( lg .) is cut tangentially. 
b.g., pollen-grains; pi., plinth; pl.j., plinth jacket ; 5., sinus; t.s., tapetal septum ; Is., tissue of 
plinth. J. 12 (Duisburg), x 42 (see p. 28). 
Fig. 25. Longitudinal section of plinth and lagenostome, enlarged from Fig. 28. me., micropyle ; 
m. m., micropylar membrane, still adhering to the testa; lg., lagenostome with cells preserved 
on the left ; pi., plinth cavity ; Is., lens, slightly displaced ; p.g., pollen-grains. J. 9 (Duisburg), 
x ico (see p. 30). 
Fig. 26. The same section as Fig. 24, through micropyle (me.), showing mucronate apex of 
seed. A 1 , A 3 , major ribs; m.co., micropylar cone ; j., sinus. J. 12 (Duisburg), x 17 (see p. 28). 
Fig. 27. Oblique transverse section near base of seed, showing the four vascular bundles (v.b.) 
corresponding to the major ribs (A 1 , A 2 , A 3 , A 4 ), minor ribs (r x , r 2 , r 3 , r 4 ). bl., ‘blow-off’. Q. 18 
(Shore), x 28 (see p. 29). 
Fig. 28. Same seed as in Fig. 25, showing the lagenostome (> lg .), plinth jacket (plj.), the lens 
(Is.), plinth (pi.). J. 9 (Duisburg), x 25. 
Fig. 29. Longitudinal section of nucellar apex and testa, showing two loculi (loc.) of major 
ribs, ‘blow-off’ layer (bl.), lagenostome (lg.). plj., plinth jacket; plintL ; s., sinus; Is., lens; 
pd ., pad of tissue on tapetal septum. J. 3 (Duisburg), x 72 (see p. 29). 
Fig* 30. Nearly longitudinal section passing out through two major ribs at the apex in which 
the loculi are cut obliquely (loc.) ; the lens (Is.) is seen in position with the descended pad (pd.). 
bl., ‘blow-off’; v.b., vascular bundle; pl.j., plinth jacket; s., sinus; lg, lagenostome; pi., plinth. 
J. 3 (Duisburg), x 17 (see p. 30). 
Fig. 31. Section tangential to seed and doubly oblique. The upper lateral ribs (r 1 , A 2 ) are 
rendered obtuse, the terminal ribs (A 1 , r 2 ) are exaggerated, and the basal laterals (r 3 , A 4 ) have 
become cuspidate, through the plane of section, v.b?, v.b?, v.b. 4 , vascular bundles; bl., ‘ blow-off ‘ ; 
pl.j., plinth jacket. J. 6 (Duisburg), x 17 (seep. 30). 
