138 THE PROTOZOA 



flagella, one being directed forward and used in locomotion, the others directed 

 backward and trailed after the organism. Nutrition is hoiozoic, and all of the 

 forms included are colorless. 



Family 1. Boconiiae. Small naked forms in which there is only a slight difference, 

 if any, between the flagella. Genera : Bodo Stein ('78) ; Phyllomiliis Stein 

 ('78) ; Colponema Stein ('78) ; Oxyrrhis Dujardin ('41). 



Family 2. Trimastigidse. With two accessory flagella. Genera: Dallingeria 

 Kent ('81) ; Trimastix Kent (/Si). 



Order 4 P0LO1ASTIGIDA. The body is invariably without a shell, and is provided 

 with a delicate membrane, which allows more or less amoeboid movement. The 

 number of flagell.a varies from three to many, and the number of mouth open- 

 ings, or food-taking areas, likewise varies. Nutrition is hoiozoic. They increase 

 by longitudinal division. 



Tribe (. Astomea. Polymastigida with many flagella and without a mouth opening. 

 Genera: Mullicilia Cienk. ('8i); Grassia Fisch ('85). 



Tribe 2. Monostomea. The anterior part is provided with a large mouth opening at 

 the base of the four or six flagella. Genera: Collodictyon Carter ('65 ) ; Tetra- 

 mittis Perty ('52); Monocercomonas Grassi ('82); Trichomonas Donne" ('37); 

 Megastoma Grassi ('8 r ). 



Tribe 3. Distomea. The flagella are separated into two symmetrical groups, with a 

 mouth area at the base of each group. Genera: Trigonomonas Klebs ('93) ; 

 Hexamitiis Dujardin ('38) ; 'Irepom.mas Dujardin ('39) ; Spironana Klebs C93) ; 

 Urophagus Klebs C93). 



Tribe 4. Trichonymphinea. Polymastigida, of unknown affinities, provided with 

 numerous flagella. They are parasites in the rectum of various hosts (Termites). 

 Genera: Lopliomonas Stein ('78); Leidyonella Frenzel C91) ; Triclwnympha 

 Leidy ('77) ; Jcenia Grassi ('85) ; Pyrsonympha Leidy C77)- 



Order 5. EUGLENIDA. Large forms having one or two flagella, a contractile or firm 

 body-wall, a mouth and pharynx at the base of the flagellum, and with a con- 

 tractile vacuole opening into the pharynx. They frequently form colonies and 

 are usually provided with chromatophores. Nutrition is hoiozoic, holophytic, or 

 saprophytic. 



Family 1. Euglenida. Elongate forms, with a more or less pointed end and usually 

 with one flagellum. The cuticle is marked with spiral stripings: the contractile 

 vacuole, or vacuoles, open into a reservoir, which in turn opens into the pharynx. 

 A red eye-spot, or stigma, and green chromatophores, are usuallv present. 

 Within the body there are discoid, or, occasionally, band-formed chromatophores. 

 Paramylum granules are always present. Genera: f-uglena Ehr. ('301; Colaciuui 

 Ehr. ('33) ; Eutreptia Perty ('52) ; Ascoglena Stein ('78) ; Trachelmwnas Ehr. 

 C33) ; Lepocinclis Perty ('49) ; Phacus Nitsch ('16) ; Cryptoglena Ehr. ('31 ). 



Family 2. Astasiidae. The body is elongate and usually has a striped membrane. 

 The anterior end is similar to that of Ei/g/ena, but there is no eye-spot. The 

 body is invariably colorless. Nutrition is saprophytic. Genera: Astasia Ehr. 

 C38) ; Distigma Ehr. C31I ; Rhnbdomonas Fres. ('58) ; MenoidiumPexty ('52) ; 

 Atractonema St. ('78) ; Sphennmoiias Stein (78). 



Family 3. Peranemidae. The bodv is either stiff or plastic, and usually symmetrical. 

 The anterior end bears either one or two dissimilar flagella, which are more or 

 less deeply sunk in the body. A distinct mouth is found at the base of the 

 flagella. Nutrition is hoiozoic. Genera: A. With plastic body and one flagel- 

 lum : Eiiglenopsis Klebs C93) ; Peranema Dujardin C41 1 ; Urceolus Meresch- 

 kowsky ('77). B. With a plastic body and two flagella: Heteronema 

 Dujardin ('41); Dineina Perty C76) ; Zygoselmis Duj. ('41 )• C. With a 

 constant body form and one flagellum : Scytomonas Stein ('78) ; Petalomonas 



