60 ] The Classification of Lower Organisms 



Family 4. Dinobryina Ehrenberg Infusionsthierchen 122 (1838). Family Dino- 

 hryaceae Engler in Engler and Prantl Nat. Pflanzenfam. I Teil, Abt. 2: 570 (1897). 

 Pigmented or colorless cells of the characters of Ochromonas or Monas, sheltered in 

 loricae, that is, in transparent open shells, solitary or colonial. The pigmented 

 examples have generally been referred to Ochromonadaceae (or whatever), the 

 colorless to Monadidae (or whatever). Pigmented, solitary, flagella markedly 

 unequal: Epipyxis, Stylo pyxis; flagella apparently equal: Chry so pyxis Stein {Dere- 

 pyxis Stokes). Pigmented, forming branching colonies: Dinobryon, Hyalobryon. 

 Poteriochromonas Scherffel resembles Stylopyxis, but the protoplast can project 

 pseudopodia from its lorica, thus supplementing photosynthesis by predatory nutri- 

 tion. Non-pigmented, solitary, flagella markedly unequal: Stokesiella; flagella ap- 

 prrently equal: Diplomita. Non-pigmented cells in colonies quite of the character 

 of those of Dinobryon: Stylobryon. 



Family 5. Hymenomonadacea [Hymenomonadaceae] Senn in Engler and Prantl 

 Nat. Pflanzenfam. I Teil, Abt. la: 159 (1900). Family Coccolithophoridae Lohman 

 in Arch. Prot. 1: 127 (1902). Family Hymenomonadidae Doflein. Family Cocco- 

 lithidae Poche in Arch. Prot. 30: 157 (1913). Order Syracosphaerinae and family 

 Pontosphaeraceae Schiller in Arch. Prot. 51: 8 (1925). Families Syracosphaeraceae, 

 Halopappaceae, Deutschlandiaceae, and Coccolithaceae Kampter. Family Thora- 

 cosphaeracee Schiller in Rabenhorst Kryptog.-Fl. Deutschland ed. 2, 10, Abt. 2: 156 

 (1930). Y3imi\it5 Syracosphaeridae, Calcisolenidae, Thoracosphaeridae, and Braad- 

 rudosphaeridae Deflandre in Grasse Trait6 Zool. 1, fasc. 1: 452, 457, 458 (1952). 

 Family Discoasteridae Tan Sin Hok. Suborder Coccolithina Hall Protozoology 130 

 (1953). Solitary cells with one or two brown plastids, usually with two apparently 

 equal flagella, having a thin cell wall from which project bodies of calcium carbonate 

 (coccoliths) of definite form. 



More than twenty genera and nearly 150 species have been described (Lohman; 

 Schiller; Kamptner, 1940). Neither the number of species nor the variety of form 

 appears to warrant making more than one family of the group. Nearly all examples 

 are marine. In Pontosphaera, Calyptosphaera, and allied genera, the coccoliths are 

 disks or hemispheres, sometimes umbonate and sometimes marked by one or more 

 pits. In Syracosphaera the coccoliths, or a few of them near the insertion of the 

 flagella, bear horn-like projections. In Najadea, Halopappus, and Calciconus, each 

 cell bears a whorl or elongate bristles. Cells of Calcisolenia are fusiform, without 

 flagella, with an armor of two layers of spiral bands of calcareous matter. In Hymen- 

 omonas and Coccolithus Swartz 1894 [Coccosphaera Wallich 1877, non Perty 1852; 

 Coccolithophora Lohman 1902) the coccoliths are punctured and accordingly ring- 

 shaped; Hymenomonas difi"ers from most of the group in occurring in fresh water. In 

 Discosphaera and Rhabdosphaera the punctured calcareous bodies are drawn out to 

 the form of tubes, spools, or trumpets. 



These obscure organisms are not without importance. They occur in all oceans, 

 being most abundant in gulfs, such as the Adriatic, where the salinity is diminished 

 by rivers (Schiller, 1925). According to Bernard (1947) turbidity in the Mediter- 

 ranean depends chiefly on this group. Coccoliths are abundant in the ooze on the 

 bottoms of oceans. They occur as fossils as far back as the Cambrian, being par- 

 ticularly abundant in certain Cretaceous deposits. 



Family 6. Phaeothamnionacea [Phaeothamnionaccae] Pascher in Siisswasserfl. 

 Deutschland2: 113 ( 1913). Family Chrysotrichaceae Fascher (1914). Family Nema- 

 tochrysidaceae Pascher (1925). Brown organisms, minute, marine, epiphytic, filamen- 



