Family Blepharocorythidae

In this holotrichasin, trichostomorid family, somatic ciliation is reduced to a few anterior and posterior fields, with 1 or 2 groups of anal cilia near the cytopyge and 2 or 3 distinct anterior groups. The cytostome is anteroventral, and opens into a long, ciliated cytopharynx.

Genus Blepharocorys

There are 3 (oral, dorsal and ventral) ciliary zones at the anterior end and 1 caudal ciliary zone. There is a deep oral groove near the anterior end.

Blepharocorys uncinata (Fiorentini, 1890) Bundle, 1895 is elongated and irregular in shape, with a slightly convex dorsal side, a slightly concave ventral side and more or less rounded ends; it measures 55 to 74 by 22 to 30 u. A corkscrew-like anterior process which makes 2 turns projects from the anterior end and also passes thru the body dorsal to the cytopharynx, ending just behind it. There is a large, ciliated vestibule at the anterior end which leads to a cytostome opening into a ciliated cytopharynx which extends dorso-posteriad and then bends sharply ventrad and disappears at the posterior half of the body. The macronucleus is heart-shaped. There is a single posterior contractile vacuole. Hsiung (1930) found this species in the cecum of 21 and the colon of 4 out of 46 horses in Iowa.

B. valvata (Fiorentini, 1890) Bundle, 1895 is more or less elliptical and flattened bilaterally. It measures 52 to 68 by 20 to 27 u. The vestibule is small and has a beak-like dorsal plate. The macronucleus is more or less kidney-shaped. Hsiung (1930) found this species in the cecum of 1 and the colon of 4 out of 46 horses in Iowa.

B. jubata Bundle, 1895 resembles B. valvata, but the dorsal plate guarding the vestibule has 2 teeth. It measures 33 to 60 by 17 to 23 u. The cytopharynx extends backward and upward and then again turns backward. The macronucleus is more or less ovoid. Hsiung (1930) found this species in the cecum of 22 and the colon of 4 out of 46 horses in Iowa.

B. curvigula Gassovsky, 1919 also resembles B. valvata, but its dorsal plate is more or less rhomboid. The long cytopharynx extends backward and upward, and finally bends in a smooth, 180° curve. The macronucleus is more or less ovoid, Hsiung (1930) found this species in the colon of 12 out of 46 horses in Iowa.

B. angusta Gassovsky, 1919 resembles B. valvata, but is more elongate, measuring 58 to 78 by 20 to 25 u. The dorsal plate is more or less rhomboid. The macronucleus is irregular. Hsiung (1930) found this species in the colon of 8 out of 46 horses in Iowa.

B. cardionucleata Hsiung, 1930 resembles B. curvigula, but its macronucleus is heart-shaped, with an anterior base and a posterior apex. It measures 48 to 62 by 17 to 23 u. Hsiung (1930) found it in the colon of 1 out of 46 horses in Iowa.

Genus Charonina

There are 2 caudal and 3 anterior ciliary zones, and an anterior knob is present on the body. This genus was originally named Charon by Jameson (1925), but this name is a homonym (Corliss, 1960).

Charonina equi (Hsiung, 1930) Strand, 1928 is lanceolate and measures 30 to 48 by 10 to 14 u. The cytostome occupies nearly the whole ventral side of the anterior knob and leads to a prominent cytopharynx which extends straight down to the middle third of the body. The macronucleus is large and elongate. Hsiung (1930) found this species in the colon of 3 out of 46 horses in Iowa.

Genus Ochoterenaia

There are 3 ciliary zones at the anterior end and 2 at the posterior end. One of the latter is borne on a caudal appendage which arises ventral to the cytopyge. There is a beak-like dorsal plate like that of Blepharocorys.

Ochoterenaia appendiculata Chavarria, 1933 is more or less elliptical and is flattened bilaterally. It measures 58 to 72 by 24 to 33 u with a mean of 66 by 28 u. The vestibule is prominent. The macronucleus is more or less kidney-shaped. Chavarria (1933a) found this species in the rectum of horses in Mexico.