191-i] Setchell: The Scinaia Assemblage 103 



Pacific Coast of North America extending from La Paz at the month 

 of the Gnlf of California north to San Pedro and Santa ]\Ioniea, 

 California, and may be expected as far north as Santa Barbara, 

 California. 



Scinaia latifrous is nearly related to Scinaia complanata, from 

 which it is amply distinguished by the marginal position of the great 

 majority of the cystocarps. It differs in several minor details also, 

 as well a.s being a larger and broader, bnt slightly less branched plant. 

 In structural peculiarities it resembles Scinaia Johnstoniae, which 

 inhabits the selfsame territory with it. Scinaia Johnstoniae, however, 

 is barely if at all flattened and its cystocarps are uniformly scattered 

 with no tendency whatsoever towards marginal aggregation. From all 

 other species, as here included, it is amply distinct. 



From Scinaia Cottonii, Scinaia latifrons is to be separated on 

 account of its larger, more ample frond, slight differences in the shape 

 and dimensions of the utricles, and the greater tendency to intra- 

 marginal aggregation of the cystocarps. 



Scinaia latifrons is the broadest and most conspicuous species of 

 the genius, being, in its most ample development, nearly if not quite 

 twice as broad as any other species. There are other broad species, 

 however, existing, and a full study of all material now in different 

 herbaria may at some time alter the claims of this species to superiority 

 in this line. Any detailed study of the development was precluded 

 by the lack of abundant material, for most of the specimens are some- 

 what battered, but the punctum vegetationis is broad and slightly con- 

 cave and the axial strand is plainly evident for 1-2 mm., then broadens 

 out and loses its identity. 



Scinaia Cottonii sp. nov. 



Plate n, fig. 24. 



Scinaia complanata Cotton, in Kew Bulletin, No. 7, }). 260, 1907 (as to Japanese 

 plant only). 



Plant rose red, 4-5 cm. high, 5-7 times dichotomous, axils moder- 

 ately ])road more or less acute, branches attenuated d(nvnwards, flat- 

 tened, not constricted, 3-10 mm. in diameter (dried) ; axis not visible; 

 cystocarps scattered, with some tendency toward intramarginal aggre- 

 gation; — epidermis of a layer of utricles which are nearly cubical 

 to rectangular oblong, lf)-20/x (T) by 13-17/* (R), flat-topped; hypo- 

 dermis loose; corticating layer narrow, loose; antheridia in small 

 clusters, scattered ; cystocarps not examined. 



