Type host: Spermophilus lateralis (Say, 1823).

Synonyms: Eimeria callispermophili [lapsus McAllister et al., 1991]; E. callosphermophili [lapsus]; E. callospermephili [lapsus]; E. citelli; E. monacis; E. os; E. perforoides.

Other Names: E. assaensis.

Hosts: Cynomys gunnisoni; C. leucurus; C. ludovicianus; Marmota baibacina; M. bobak; M. flaviventris; M. monax; M. sibirica; Spermophilus armatus; S. beecheyi; S. beldingi; S. columbianus; S. citellus; S. elegans; S. erythrogenys; S. franklinii; S. fulvus; S. lateralis; S. mexicanus; S. relictus; S. richardsonii; S. spilosoma; S. townsendii; S. tridecemlineatus; S. undulatus; S. variegatus.

Type locality: North America, USA, California, Placer County.

Other localities: Asia: Buriatia; Kazakhstan; North America: Canada, Alberta; USA, Colorado, Idaho, Illinois, Iowa, Montana, New York, New Mexico (unpubl. data), Pennsylvania, Texas, Utah, Wyoming; Central America: Mexico.

Description of oocyst: Oocyst shape: subspheroid; wall thickness: 1.0-1.5; layers: 1 or 2; outer layer proportion of total thickness: not given; outer layer colour: yellow; outer layer texture: smooth; inner wall characteristics: smooth; micropyle: absent; OR: present; OR characteristics: homogenous and clear or granular; OR L x W: 3-5 x 3-5; PG: present; number of PGs: a few; PG shape: not given; PG L x W: not given; size: 19.2 x 16.0 (16-22 x 16-22); L/W ratio: 1.1 (1.0-1.1). Distinctive features of oocyst: transparent appearance with large, clear OR; original description states that the outer wall is slightly rough and one layer thick. In the original photomicrograph, the wall of the sporulated oöcyst appears smooth; all other authors have reported it as smooth. The number of layers has been reported as 1 or 2 by various authors.

Description of sporocysts and sporozoites: Sporocyst shape: subspheroid; size: 10.2 x 8.5; SB: present; SB L x W: not given; SB characteristics: pointed; SSB: absent; PSB: absent; SR: present; SR characteristics: meagre, consisting of a few granules; SR size: not given; SP: not described. Distinctive features of sporocyst: none.

Material deposited:: USNPC No. 87249 (phototype).

Remarks: Eimeria callospermophili was described by Henry (1932) in S. lateralis. In 1931, Crouch & Becker found E. perforoides (described as a new species) and "E. monacis" in M. monax. However, their description of E. perforoides matched Fish's (1930) description of E. monacis while the form they called E. monacis matched E. callospermophili. We consider Crouch & Becker's (1931) E. perforoides to be E. monacis and their E. monacis to be E. callospermophili. Machulsky (1941) identified E. os in M. sibirica, but his species matches Crouch & Becker's (1931) E. monacis (= E. callospermophili, see above) not the description of E. os. Svanbaev (1962) reported E. callosphermophili (sic) from Meriones tamariscinus, but Levine & Ivens (1965) thought Svanbaev saw E. assaensis. However, there is no illustration, so E. assaensis is a species inquirenda. Dorney (1965) reported E. monacis in M. monax, but the description and photomicrograph are indistinguishable from E. callospermophili and do not match the original description of E. monacis by Fish (1930). The photomicrograph labelled E. citelli in Abenov & Svanbaev (1979) also looks like E. callospermophili. Fleming et al. (1979) and McQuistion & Wright (1984) reported E. monacis from M. monax. They both used Dorney (1965) to aid their identifications, so what they all called E. monacis was probably E. callospermophili. Nukerbaeva & Abenov (1979) described two morphotypes of E. perforoides (=E. monacis, see above). The description and photomicrograph of Nukerbaeva & Abenov's (1979) round form appear to be of E. callospermophili. Abenov & Svanbaev (1982) presented a photomicrograph of E. citelli that strongly resembles E. callospermophili, while the oocyst in their photomicrograph of E. callospermophili is incompletely sporulated.

References: Abenov (1980); Abenov & Svanbaev (1979, 1982); Crouch & Becker (1931); Dorney (1965); Fish (1930); Fleming et al. (1979); Henry (1932); Hilton & Mahrt (1971); Levine et al. (1958); Levine & Ivens (1965); McAllister et al. (1991); McQuistion & Wright (1984); Machulsky (1941, 1949); Nukerbaeva & Abenov (1979);Seville (1997); Seville et al., (1992); Seville & Stanton (1993b); Shults et al., (1990); Stanton et al. (1992); Svanbaev (1960, 1962); Thomas & Stanton (1994); Todd & Hammond (1968a); Torbett et al. (1982); Veluvolu & Levine (1984); Wilber et al. (1994).