56 INVERTEBRATE ZOOLOGY 



In fact, at the present time many bacteriologists are now main- 

 taining that bacteria may belong to the animal kingdom. 



Outline of Classification 



Phylum Protozoa. — Single-celled animals or cell aggregates in which there 

 is no histological differentiation of somatic tissues. 



A. Subphylum Plasmodroma. — Protozoa lacking cilia throughout life. 

 I. Class Mastigophora. — One or more vibratile flagella. 



a. Subclass Phytomastigina. — Plantlike flagellates. 



1. Order Chrysomonadina. — One or two flagella; small; frequently 

 with pseudopodia; yellow-brown chromatophores; spore formation 

 in cysts. Dmobryon (Fig. 14), Chromulina (Fig. 17), Chnjsopyxis, 

 Uroglena, Synura. 



2. Order Cryptomonadina. — One or two flagella; small; constant 

 body form; yellow, l)rown, blue, or green chromatophores; chiefly 

 marine. Chilomonas (Fig. IS), Chrysidella, Cyathomonas, 

 Cryptomonas. 



3. Order Dinoflagellata. — Two flagella, one usually in circular 

 furrow; yellow-brown chromatophores; test usually present; 

 chiefly marine. Ceratiurn, Nodiluca, Peridinium, Gymnodiniiim, 

 Haplozoo7i. 



4. Order Euglenoidina. — Relatively large; one or two flagella; 

 green or red chromatophores or wanting; complex vacuole system; 

 usually a cytostome; chiefly fresh-water. Euglena, Phaciis, 

 Peranema (Fig. 19), Astasia, Trachelomonas. 



5. Order Phytomonadina. — Two flagella; green or yellow chroma- 

 tophores; colony formation characteristic; sex differentiation in all 

 degrees. Chlamydomonas, Gonium, Spondylomorum, Pleodorina, 

 Pandorina Eudorina, Platydorina, Volm x. 



b. Subclass Zoomastigina. — Animal-like flagellates; no chromato- 

 phores; no chlorophyll; vacuole simple; kinetic and locomotor 

 elements highly differentiated. 



6. Order Protomastigina. — One to few flagella; pseudopodia 

 common; one nucleus. Mastigamoeha, Mastigella (Fig 15), Actino- 

 moTMS, Dimorpha. 



7. Order Protomonadina. — One or two, rarely three, flagella; one 

 nucleus; minute; many parasitic. Trvvanosoma (Fig. 23), Leish- 

 mania, Crithidia, Monas, Bodo, Bicosoeca, Anthophysa. 



8. Order Polymastigina. — Few to many flagella; one, two, or 

 many nuclei; many parasitic in digestive tract; colony formation 

 unknown. Giardia, Chilomastix, Stephanonympha, Dinenympha. 



9. Order Hypermastigiua. — Many flagella; one nucleus; 

 parasitic in insects; highly specialized. Lophomonas, Joenia, 

 Trichonympha. 



n. Class Sarcodina. — Usually lack cell membrane; floating or sus- 

 pended forms or with pseudopodia for locomotion. 



a. Subclass Actinopoda. — Unusuallj" spherical; typically floating; 



axopodia; highly alveolar. 



