Synonyms: Paracoccidium prevotis Laveran and Mesnil, 1902; Eimeria prevunti (Laveran and Mesnil, 1902), Yakimoff and Matikaschwili, 1933 lapsus.

Type host: Pelophylax lessonae (Camerano, 1882), Pool frog.

Other hosts: None reported to date.

Type locality:EUROPE: France, west of Paris.

Geographic distribution: EUROPE: France.

Description of oocyst: Oocyst shape: mostly globoidal to ovoidal; number of walls:1 ; wall thickness: "thin"; wall characteristics: smooth; L x W: variable--globoidal forms are 16-18, while ovoidal forms are 20-22 x 12-15; L/W ratio: variable; M: absent; OR: present; OR characteristics: spheroidal, ~5-6 wide, composed of a large vacuole surrounded by coarse granules; PG: unknown. Distinctive features of oocyst: thin, single-layered wall and an OR with a vacuole surrounded by granules.

Description of sporocysts and sporozoite: Sporocyst shape: initially fusiform, but the sporocyst wall eventually diappears leabing 8 SZ free in the oocysts; L x W: unknown; L/W ratio: unknown; SB: present as a small nipple-like structure at one end of the sporocyst; SSB: absent; PSB: absent; SR: present; SR characteristics: small mass composed of coarse granules between SZ; SZ: elongate, ~10-12 long, with 1 obvious RB. Distinctive features of sporocysts: sporocyst wall disappears soon after sporulation is completed, leaving the 8 SZ and the remaining OR and SR free within the oocyst.

Prevalence: Unknown.

Sporulation: Unknown. The initial sporoblast, ~7 wide, elongates to form sporocysts and OR. Upon sporocyst formation, the SZ are arranged head to tail therein.

Prepatent and patent periods: Unknown.

Site of infection: Mid-gut epithelial cells.

Endogenous development: Both merogony and gamogony occur above the N of the intestinal epithelial cell. Young meronts were round, ~4, and limited by a fine membrane. Ripe meronts were ovoidal, ~21.5 x 16.8, and produced up to 40 merozoites (38–44), each ~6.2 x 1.5. Mature microgamonts were 21.4 x 19.8 and give rise to comma-shaped microgametes, 5–6 x 0.7, with 2 flagella which are unequal in length (11 and 8 long). A vacuole is visible within the granular cytoplasm of the mature macrogamonts, which are round, ~10, and have a distinct N with a conspicuous karyosome. Doflein (1909) said that the macrogamont formed the covering only after fertilization and that the sporoblast of the zygote did not go through a pyramid stage, as seen in many coccidia.

Materials deposited: None.

Remarks: Laveran and Mesnil (1902a) created the subgenus Paracoccidium in their belief that disintegration of the sporocyst wall soon after sporulation was completed might represent an intermediate phylogenetic type of development; however, work with other amphibian coccidia (e.g. E. canaliculata; E. fragilis) shows that this is not an uncommon phenomenon. Doflein’s (1909) line drawing of E. prevoti shows that the oocysts he saw were ellipsoidal. Boulard (1975) redescribed the species and its endogenous development, also from pool frogs, which he caught in Normandy and most of the measurements above are from his paper. Boulard (1975) provided a detailed line drawing of a sporulated oocyst that showed a distinct SB on the sporocysts before they disintegrated, a detail omitted by Laveran and Mesnil (1902a) in their original work. Boulard’s (1975) young oocysts taken from feces measured 16.5 x 12.8 (15–17 x 12–14), with a L/W ratio of 1.3; after sporulation, the oocysts were 17.4 x 12.6 with a L/W ratio of 1.4. The OR was a spherical mass of granules, ~4.5 x 3.