Family Gymnophallidae Odhner, 1905

Bartolius Cremonte, 2001

Bartolius pierrei Cremonte, 2001

Location: small intestine.

Localities: Fracasso beach and Colombo beach (Península Valdés) and Rada-Tilly, Chubut Province;

Punta Medanosa and Punta Loyola, Santa Cruz Province (Argentina). Life history: H 1 and H 2: Darina solenoides (King). References: Cremonte (2001), Cremonte & Ituarte (2003), Cremonte (2004).

Gymnophallus Odhner, 1900

Gymnophallus deliciosus (Olsson, 1893)

Other host: Larus argentatus Pontoppidan

Location: small intestine.

Localities: Arctowski Station, South Shetland Islands (Antarctica). Life history: H 1: Acmaea cassis (Eschscholtz), Mytilus edulis (L.). References: Freiler (1986), Zdzitowiecki et al. (1989).