Location: Unknown. Oocysts found in feces.
Geographic Distribution: North America (California, Minnesota, Maryland, Georgia), Hawaii, USSR (North Caucasus).
Prevalence: Unknown. This species appears to be relatively uncommon.
Morphology: This species was described by Henry (1931). The oocysts are ovoid or ellipsoidal, 16 to 22 by 10 to 13 u. The oocyst wall is brown, opaque, and studded with spines about 1 u long and 1 u apart. A micropyle is absent. An oocyst polar granule is present. An oocyst residuum is apparently absent. The sporocysts have a Stieda body. A sporocyst residuum is apparently present (Henry's description is ambiguous). The sporulation time is 11 to 12 days.
Pathogenesis: This species is only slightly pathogenic if at all. Andrews and Spindler (1952) observed no diarrhea or other signs in an infected pig which passed as many as 7 million oocysts per gram of feces.