76 Howe : Phycological studies 



Branches of the lowermost whorls commonly one or more times 

 di-trichotomous and sterile ; primary branches (branches of the 

 first order) of the remaining whorls mostly giving rise to a terminal 

 stalked sporangium and two (in IV. stipitata sometimes three) ster- 

 ile branches, the latter springing from near the base of the spor- 

 angium. Sterile branches of the second order in adult stage either 

 enlarged and vesicular distally, the inflations strongly coherent 

 .and forming a unlstratose cortex wMth more or less hexagonal 



Cokeri) merely subfusiform and imperfectly co- 

 forminer a cortex. Each of the sterile branches 



facets, or in (N. 



of the second order terminating in a single simple or one or more 

 times di-trichotomous, soon deciduous hair. Sporangia subglobose, 

 obovoid, pyriform, or somewhat cylindrical, enclosed in thick cal- 

 careous capsules, these sometimes coherent ; the sporangium-stalk 

 often at length cut off from the supporting primary branch by a 

 basal constriction and plug. Each sporangium enclosing a single 

 spore (gametangium ?), this furnished with an operculum at its 

 basal (proximal) end. 



Type species yV. dumetosa Lamour. 



Hairs monomorphous ; ends of brandies of the second order form- 

 ing a cortex with distinct facets. 

 Sporangia strongly calcified but mutually free. 



Primary branches 500-1000// long, 15-35 times as long 



as their median diameter. 

 Primary branches coherent by intercalary l!me-de- 

 posits inlo flat, cuneate, flabelliform, or somewhat 

 annular transverse scales or bands of mostly 3-8 

 branches, easily caducous; plants mostly 15-20 



T 



times as long as thick. I. N. diiinetosa. 



Primary branches strongly calcified but free, or, at 



most, very irregularly and loosely coherent, per- 

 sistent ; plants mostly 6-12 times as long as thick. 



1 



2. N, van Bossecte 



Primary branches 240-410/^ long, 4-10 times as long as 



their median diameter. 



Plants 26-40 mm. long ; facets of the cortex firm- 

 walled, not calcified on the outer stirface, occa- 

 sionally in threes ; sporangia first appearing at 

 about 15 mm. from base of mature plant. 3. N, sti/^itata. 



Plants 8-20 mm. long; facets of the cortex thin- 

 walled and very mucilaginous, strongly calcified 

 at first on the outer surface, always in pairs ; 

 sporangia first appearing at about 2-6 mm. from 

 base of mature plant. 4. N', mucosa. 



Sporangia coherent laterally by their calcareous capsules, the 

 plant thereby appearing transversely annulate in the lower 

 fertile parts. 



5. N'. an mi lata* 



