OTHER FLAGELLATES 



125 



of coccoliths is present. This suborder 

 contains 4 families, 2 of which contain 

 parasitic or coprophilic species. 



FAMILY CHROMULINIDAE 



Members of this family have a single 

 flagellum. 



Genus OIKOMONAS Kent, 1880 



Members of this genus lack chromato- 

 phores, lorica or test. They are solitary. 

 The nucleus is near the center of the body. 

 The single flagellum arises from a basal 

 granule near the body surface. Cysts are 

 formed, at least in the free-living species. 

 This genus is the colorless homolog of 

 Chroninlina. Its parasitic species are 

 poorly known. 



Oikomonas communis Liebetanz, 

 1910 and Oikomonas mini)>ia Liebetanz, 

 1910 were both described from the rumen 

 of cattle. They are said to differ in size, 

 the former being up to 11 /i long and the 

 latter more than 4(i long; this is probably 

 not a valid difference. Das Gupta (1935) 

 found 0. communis in the rumen of goats 

 in India. 



Oikomonas equi Hsiung, 1930 was 

 found in the cecum of 8 horses in Iowa. 

 It is usually spherical or ovoid and swims 

 in a jerky manner. The nucleus has a 

 large, central endosome and the cytoplasm 

 is filled with small, dark-staining gran- 

 ules. The body is 3. 5 to 1 [i long and 3 to 

 5. 5/1 wide. The flagellum is about 20 /i 

 long. 



Genus SPHAIROMONAS 

 Liebetanz, 1910 



The body is spherical or ellipsoidal, 

 with a more or less central nucleus. A 

 single, long flagellum arises from a basal 

 granule on the nuclear membrane. This 

 genus is poorly known and has apparently 

 not been studied by modern methods. It 

 is closely related to Oikomonas and may 

 even be a synonym of that genus. Several 



species have been named, all parasitic, 

 but most of them are probably the same. 



Sphaeromonas communis Liebetanz, 

 1910 (syns. , S. minima, S. maxima, S. 

 liebeta)izi, S. rossica) occurs in the rumen 

 of the ox and goat and in the cecum and 

 feces of the guinea pig. It may also be 

 coprophilic. Liebetanz (1910) and Braune 

 (1914) found it in the rumen of cattle in 

 Europe, Becker and Talbott (1927) found 

 it in the rumen of a few cattle in Iowa 

 (calling it, however, Monas communis), 

 and Fonseca (1916) found it in cattle and 

 goats and also in the guinea pig in Brazil. 

 Yakimoff et al. (1921) found it in the 

 guinea pig in Russia. The body is spher- 

 ical or ellipsoidal, 3 to Mfi in diameter. 

 The cytoplasm contains many dark-staining 

 granules. 



Genus CAVIOMONAS Nie, 1950 



The body is naked, without chromato- 

 phores and with a vesicular nucleus at the 

 anterior end. One flagellum arises from 

 the nuclear membrane. A band-like peri- 

 style arises from the nuclear membrane 

 opposite to the origin of the flagellum and 

 extends posteriorly along the periphery of 

 the body surface; it stains with hematoxylin 

 and protargol. Cytostome and contractile 

 vacuoles are absent. 



Caviomonas mobilis Nie, 1950 occurs 

 in the cecum of the guinea pig. The body 

 is ovoid to elongate carrot-shaped and the 

 posterior end is often pointed. It measures 

 2 to 7 by 2 to 3 n with a mean of 4 by 3 /j. . 



FAMILY OCHROMONADIDAE 



Members of this family have 1 long 

 and 1 short flagellum. 



Genus MONAS Muller, 1773 



The body is active and plastic. Chrom- 

 atophores are absent. This genus is the 

 colorless homolog of Ochromonas . Reyn- 

 olds (1934) recognized 13 free-living spe- 

 cies, and in addition there is at least 1 

 coprophilic one. 



