MORPHOLOGY AND TAXONOMY OF MASTIGOPHORA 301 



Sub-family 2. Coccolithophorinw 



1. Perforated discs without floating processes 



Genus Coccolithophorn 

 Perforated discs with floating processes ... 2 



2. Floating processes club-shape Genus Rhabdosjjhcera 



Floating processes with terminal discs 



Genus Discosphcera 

 Famih' 5. Silicoflagellidse. 



1. Silicious skeleton a simple ring Genus Mesocena 



Basal ring with bars to form hat-like skele- 

 ton 2 



2. Silicious bars one to four in number . Genus Dictyocha 

 Silicious bars more than four in number ... 3 



3. Simple apical ring formed by fused bars 



Genus Distephanus 

 Complex apical ring Genus Cannophilus 



Sub-order 2. Rhizochrysidina. 



1. Naked forms 2 



With tests or houses 4 



2. Solitary forms Genus Rhizochrysis 



Colonial forms 3 



3. Cham-form or band-like colonies. . .Genus Chrysidiastnon 

 Wheel-form colonies Genus Chrysostephanosphcera 



4. Tests oval or ellipsoid , stalks long and fine 



Genus Stylococcus 

 Tests with broad bases; sessile Genus Lagynion 



Sub-order 3. Chrysocapsina. 



Growth general, not limited to ends of 



branches Family Chrysocapsid.e 



Growth lunited to ends of branches ; apical 



Family Hydrurid.e 

 Family 1. Chrysocapsidse. 



Pahnella aggregate small; not branching 



Genus Chrysocaj)sa 

 Palmella aggregate branched or irregular 



Genus Phceosphcera 

 Family 2. Hydruridae. 



One genus with characters of family. . .Genus Hydrurus 



Order II. CRYPTOMONADIDA. 



Motile flagellated stage predominant 



Sub-order 1. Eucryptomoxadixa 

 Pahnella-stage predominant Sub-order 2. Ph.eoc.^sina 



Sub-order 1. Eucryptomonadina. 

 Anterior end obliciuely truncated ; with furrow 



Familj' 1. Cryptomoxadid.e 

 Cells bean-shape; furrow lateral, near equator 



Family 2. Nephroselmid^ 



Family 1. Cryptomonadidse. 



1. Furrow median, not deej^ened to a gullet. . 2 

 Furrow insunk, forming distinct gullet. ... 5 



