Type host: Sorex ornatus Merriam, 1895 (Syn. S. californicus), Ornate shrew.

Other hosts: Sorex araneus Linnaeus, 1758, Eurasian common shrew; Sorex minutus Linnaeus, 1766, Pygmy shrew.

Type locality: NORTH AMERICA: USA, California, near Berkeley.

Geographic distribution: NORTH AMERICA, USA, California; EUROPE: Lithuania; Russia.

Description of oocyst: Oocyst shape: subspheroid to ovoid to ellipsoid (?); number of walls: 1; wall thickness: <1.0: wall characteristics: thin, of uniform thickness, colorless; L x W: 19 x 14 (19-22 x 13-14); L/W ratio: 1.4; M: absent; OR: absent; PG: 1. Distinctive features of oocyst: none.

Description of sporocysts and sporozoites: Sporocyst shape: elongate ellipsoid (line drawing of Yakimoff and Gousseff, 1935); L x W: unknown; L/W ratio: unknown; SB: absent; SSB: absent; PSB: absent; SR: present (?); SR characteristics: "residual material in the sporocyst," (not shown in line drawing); SP: with a distinct RB at one end (line drawing). Distinctive features of sporocyst: elongate-ellipsoid shape.

Prevalence: 1/1 S. californicus; 1/10 (10%) S. araneus.

Sporulation: Exogenous. Oocysts sporulated in 7-8 days.

Prepatent and patent periods: Unknown.

Site of infection: Unknown. Oocysts recovered from feces and intestinal contents.

Materials deposited: None.

Remarks: Henry (1932) said the oocysts she saw were "ovoidal." However, her photomicrograph (her Fig. 10) showed an oocyst that was subspheroid, but the measurements she gave (L/W 1.4) indicate the oocyst could be ellipsoid. Yakimoff and Gousseff (1935), who gave oocyst measurements similar to those of Henry (1932), had a line drawing that clearly was ellipsoid. Neither Henry (1932) nor Yakimoff and Gousseff (1935) measured sporocysts, but the latter authors drew them as elongate ellipsoid structures and showed that each SP had a RB at one end; although a SR is mentioned by both authors as being present, it is not easily seen in the photomicrograph (Henry, 1932) or in the line drawing (Yakimoff and Gousseff, 1935). The oocysts measured by Yakimoff and Gousseff (1935) were 20.8 x 14.6 (16-22 x 12-18), but we can't determine if the oocysts they measured actually were E. soricis or a morphologically similar species. The oocysts found in the pygmy shrew from Lithuania measured 18.5-19.5 x 14-15 (Arnastauskiene and Maldziunaite, 1979).

References: Henry (1932); Yakimoff and Gousseff (1935); Arnastauskiene and Maldziunaite (1979).