THE CILIATES 



353 



E. simulans Lubinsky, 1957 measures 

 27 to 44 by 21 to 34 (i. Its body is ovoid 

 as seen from above. The macronucleus is 

 about half the body length. The contrac- 

 tile vacuole is on the mid-line of the upper 

 side of the body at the level of the micro - 

 nucleus and to the left of the upper groove. 

 This groove is narrow and long, with a 

 slit-shaped anterior half. 



E. longinucleatum Dogiel, 1925 meas- 

 ures 39 to 64 by 27 to 46 /j, and has an 

 ellipsoidal, flattened body. The macro- 

 nucleus usually extends the whole length 

 of the body from the anterior end to the 

 cytopyge. The contractile vacuole is close 

 to the upper side of the macronucleus, 

 slightly anterior to the micronucleus. 



E. rostratum Fiorentini, 1889 meas- 

 ures 27 to 51 by 13 to 23 ju and has a 

 rather long, slim, flattened body with a 

 strongly convex right side and a concave 

 left side. The macronucleus is narrow, 

 bandlike, and about half the length of the 

 body. The contractile vacuole is directly 

 anterior to the macronucleus. 



E. laterale Kofoid and MacLennan, 

 1930 measures 19 to 28 by 18 to 21 [i and 

 has a short, fairly broad, truncated ellip- 

 soidal, flattened body. The macronucleus 

 is broad and wedge-shaped, less than half 

 the length of the body, and lies in the an- 

 terior half of the body. The contractile 

 vacuole is in the middle of the upper side. 



E. nanellum Dogiel, 1922 measures 



20 to 32 by 10 to 18 p, and has an ovoid, 

 flattened body. The macronucleus is 

 thin, wedge-shaped, and longer than half 

 the body length. The contractile vacuole 

 is above the anterior end of the macro- 

 nucleus. 



E. bimastus Dogiel, 1927 measures 

 30 to 46 by 28 to 40 (i and has a subspher- 

 ical, flattened body. The macronucleus 

 is flattened, wedge-shaped, and about 

 2/3 of the length of the body. The contrac- 

 tile vacuole is above the anterior end of 

 the macronucleus. 



E. exiguum Dogiel, 1925 measures 



21 to 29 by 14 to 18 ju and has an elongate, 

 oval body. The macronucleus is rela- 



tively short and thick, being shorter than 

 half the body length, and lies in the mid- 

 dle of the body. 



E. dubardi Buisson, 1923 (syn. , E. 

 simplex Dogiel, 1925 pro parte; the true 

 E. simplex occurs in the reindeer) meas- 

 ures 30 to 50 by 20 to 29 /i and has an oval 

 or elongate oval, flattened body. The 

 macronucleus is more or less band-shaped, 

 with a somewhat broader anterior end. It 

 is about half as long as the body and lies 

 anteriorly in it. The contractile vacuole 

 is below the anterior end of the macro- 

 nucleus. 



E. vorax Dogiel, 1925 measures 60 

 to 121 by 40 to 83 ji and has an oval, plump, 

 thick body. The anterior end is often 

 smaller than the posterior. The macro- 

 nucleus is sausage-shaped, about half as 

 long as the body, and lies in the anterior 

 part of the body. The contractile vacuole 

 is to the right of the anterior end of the 

 macronucleus. 



Quite a few other species of Entodin- 

 ium have been described from various 

 ruminants. Among them are the following, 

 which Kofoid and MacLennan (1930) des- 

 cribed from the zebu: E. ellipsoideum, 

 E. acutonuc lea turn, E. pisciculum, E. 

 biconcavum, E. bifidum (Dogiel) E. 

 acutum, E. aculeatum, E. brevispinum, 

 E. laterospinmn , E. ovoideum, E. rhom- 

 boideum, E. gibberosum , E. tricostatum, 

 and E. indicum. 



Genus EPIDINIUM Crawley, 1924 



The body is elongate and twisted 

 around its main axis. The adoral zone of 

 membranelles is at the anterior end, and 

 the metoral zone elsewhere. There are 

 3 skeletal plates with secondary plates. 

 The macronucleus is simple and club- 

 shaped. There are 2 contractile vacuoles. 

 This genus occurs in the rumen and reticu- 

 lum of cattle, sheep, goats, camels, rein- 

 deer, elk, and other ruminants. 



Epidinium ecaudatum (Fiorentini, 

 1889) (syn. , Diplodinium ecaudatum) 

 measures 82 to 173 by 36 to 70 /j, and has 

 an elongate body with a convex left side and 



