Type host:Marmota monax

Synonyms: Eimeria os; E. perforoides.

Other names: Eimeria callospermophili.

Other hosts: Marmota baibacina; M. bobak; M. marmota; M. menzbieri; M. sibirica.

Type locality: North America: USA, Washington, DC, after capture, the marmot was kept in the lab.

Other localities: Asia: Buratia; Kazakhstan; North America: USA, Iowa.

Description of oocyst: Oocyst shape: ovoid; wall thickness: not given; layers: 1; outer layer colour: not given; outer layer texture: smooth; micropyle: absent; OR: present; OR characteristics: small compact mass (in drawing); OR L x W: not given; PG: absent; size: 20.0 x 18.3 (17-24 x 15-21); L/W ratio: 1.2. Distinctive features of the none.

Description of sporocysts and sporozoites: Sporocyst shape: ovoid; size, estimated from drawing: 8 x 6; SB: present; SB L x W: not given; SB characteristics: prominent; SSB: absent; PSB: absent; SR: present; SR characteristics: granular, located in centre of sporocyst (see drawings in Fish, 1930; Crouch & Becker, 1931); SR size: not given; SP: not described. Distinctive features of sporocyst: none.

Remarks: Eimeria monacis was described by Fish (1930) in M. monax. Here we synonymise E. perforoides Crouch & Becker, 1931 (20 x 14) with E. monacis because the descriptions of the two forms are indistinguishable. Svanbaev (1963) described E. os from M. menzbieri, but Levine & Ivens (1965), with whom we agree, thought it was E. monacis, presumably because Svanbaev (1963) saw an oocyst residuum (not a feature of E. os), and did not report a micropyle (which is a feature of E. os). Svanbaev (1963) also found what he called E. monacis, but Levine & Ivens (1965) gave it the new name, E. tyanshanensis. However, Svanbaev's (1963) description is inadequate and there is no illustration; therefore, E. tyanshanensis is a species inquirenda. Dorney (1965) found what he called E. monacis in M. monax, but it is indistinguishable from E. callospermophili. Fleming et al. (1979) and McQuistion & Wright (1984) also reported E. monacis from M. monax. However, they followed Dorney's (1965) paper; thus, it is likely they all observed E. callospermophili.

References: Crouch & Becker (1931); Dorney (1965); Fish (1930); Fleming et al., (1979); Iwanoff (1934); Levine & Ivens (1965); McQuistion & Wright (1984); Machulsky (1949); Nukerbaeva & Abenov (1979); Svanbaev (1963).