88 University of California Publications i)i Botany [Vol. 6 



region of a branch and consist of a three-celled branchlet bearing the 

 carpogonium with the long trichogyne at its apex. The sporogenous 

 tissue is produced directly from the apical cell, i.e., the carpogonium, 

 the middle cell, even before fecundation of the carpogonium, begins 

 to send out processes which become filamentous and later grow up 

 around the sporogenous mass as it develops. The filaments are at 

 first separate, but become pressed together so tightly that when their 

 individual cells enlarge the whole growth of filaments forms a sort of 

 parenchymatous envelope surrounding the sporogenous tissue in a 

 pyriform cavity which opens out above, forming a narrow carpostome. 

 The basal cell of the procarpic branch enlarges to form a more or less 

 conspicuous stalk-cell or pedicel. Nothing is known, apparently, of 

 the germination of the carpospore and of the early stages of any of the 

 species of Scitima. 



Each of the points connected with the cystocarp needs much further 

 discussion than is possible even after an examination of all the material 

 at the present disposal of the writer. 



Nearly all the specimens of Scinaia proper, accessible to the writer, 

 show cystocarps in the adult stage and as a rule very plainly in the 

 pressed condition. They form, to the naked eye, more or less con- 

 spicuous, larger or smaller dots of a decidedly darker color than the 

 frond. In almost all the species they are scattered over the surface 

 of the frond in no regular order. In two species, however, Scinaia 

 latifrons Howe (1911, p. 500, fig. 1, pi. 28) and Scinaia Cottonii sp. 

 nov., the cystocarps show a decided tendency to aggregate themselves 

 along the margins of the flattened fronds. 



IV. TAXONOMY 



In taking up the matter of the systematic arrangement it will also 

 be possible to amplify the preceding statements about general struc- 

 ture as the special morphology of each genus and species is considered. 

 In the following account is taken up each and every specimen accessible 

 to the writer for examination and study, and an attempt is made to 

 place each one as accurately as possible. As will be seen, considerable 

 differences are brought out and a considerable number of new names 

 proposed. It is hoped that they may be justified and made clear in 

 the following account. 



