Affinities of the Palaeozoic Seeds of the Conostoma Group. 27 
fig. 9) w.), and into this depression the summit of the micropylar cone 
slightly projected (o-oi mm.). The main cavity of the seed was nearly 
cylindrical, rounded at either end, and passing by a funnel-shaped portion 
into the tubular micropyle above. 
The megaspore cavity was about 4 -6 mm. long and 2 mm. wide, 
surmounted, as in C. oblongum , by a dome-shaped plinth which bore the 
characteristic lagenostome in a slight depression at its apex. Compared with 
Text-fig. 10. Conostoma anglo-germanicum. Series of transverse sections at the levels marked 
A, B, c, and D in the vertical reconstructions (Text -fig. 9). The ‘ blow-off’ layer is left white 
except in A and d. The testa is black and the parenchymatous tissue shaded. R 1 , R 2 , R 3 , R 4 , major 
ribs; r\ r 2 , r 3 , r 4 , minor ribs ; 61 ., ‘blow-off’; lagenostome. x about 25. 
the internal structure of C. oblongum , the nucellus was narrower and much 
longer, whilst the plinth cavity remained of about the same depth, though 
slightly less extensive in width. The plinth contents appear to have been 
as in Conostoma oblongum. 
The lagenostome was slightly higher and broader than in the other 
species, perhaps referable to the larger size of the pollen-grains in 
Conostoma anglo-germanicum, From the base of the plinth downwards, the 
