Mesodinium Stein, 1862 (ref. ID; 3540, 3690, 4352) or 1863 (ref. ID; 2013, 4613, 4971)
Class Kinetofragminophora: Subclass Gymnostomata: Order Haptorida: Family Didiniidae (ref. ID; 2013)
Family Mesodiniidae: Litostomatea (ref. ID; 4971)

[ref. ID; 2013]
Body shape pyriform but divided into two sections by a waist-like furrow. Anterior narrows apically, posterior broadly rounded. Oral aperture apical, cytopharynx with 8 to 12 protruding trichites which are forked at the anterior most end. Somatic ciliation reduced to 2 bands of cilia which arise from the central body furrow. Both bands arise from short oblique rows of kinetosomes, the posterior band consists of rows components of the anterior ciliary band are stiff and bristle-like, those of the posterior band are membranelle-like and project backwards. Macronucleus centrally located. Contractile vacuoles have been reported in both posterior and mid-lateral positions.
Quote; Colin R. Curds "British and other freshwater ciliated protozoa Part I Ciliophora: Kinetofragminophora" Cambridge University Press, 1982 (ref. ID; 2013)


Mesodinium acarus Stein, 1862 (ref. ID; 1308, 1335, 1619, 1629, 2245, 3540) or 1867 (ref. ID; 4612, 4613) reported year? (ref. ID; 1618, 5624) reported author and year? (ref. ID; 191)
Syn; Mesodinium fimbriatum Stokes, 1887 (ref. ID; 1619, 3540); Mesodinium phialinum Maskell, 1887 (ref. ID; 1619, 3540, 4613)
Description; Oral tentacles with capitate tip; salt water. (ref. ID; 1618)
Measurements; 10-16 um long. (ref. ID; 1618)
Mesodinium pulex Claparede & Lachmann, 1858 (ref. ID; 1308, 1619, 1629, 2245, 2316, 3119, 3540, 4814) reported year? (ref. ID; 1219, 1618, 3690, 3771) or (Claparede & Lachmann) Stein, 1862 (ref. ID; 3564), (Claparede & Lachmann, 1859) Stein, 1867 (ref. ID; 4612, 4613) reported author and year? (ref. ID; 4971)
Syn; Halteria pulex Claparede & Lachmann, 1858 (ref. ID; 1619) or 1859 (ref. ID; 4612, 4613) reported year? (ref. ID; 3690); Halteria rubra Lochmann, 1908 (ref. ID; 1619, 3540); Mesodinium pulex var. striata Gourret & Roeser, 1886 (ref. ID; 1619, 3540)
Description; Oral tentacles with trifurcate tips. (ref. ID; 1618)
Pyriform but was divided into two by a waist-like furrow. Somatic ciliation reduced to two bands arising from central furrow. Trichites of the cytopharynx protruded slightly. Distinctive saltatorial locomotion. (ref. ID; 2316)
Remarks; Seven populations of M. pulex were examined morphometriclaly. (ref. ID; 4814)
Measurements; Body 21-38 um long (freshwater forms), 20-31 um long (salt water forms). (ref. ID; 1618)
Size 25 um x maximum diameter of 15 um. (ref. ID; 2316)
Mesodinium rubrum Lohmann, 1908 (ref. ID; 4991, 7666) reported author and year? (ref. ID; 191)
See; Myrionecta rubra (ref. ID; 1877, 4971)
Syn; Myrionecta rubra Jankowski, 1976 (ref. ID; 4991)
Description; The ciliary structure. (ref. ID; 7666)