1. Laboratory of Veterinary Parasitology, Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
2. Department of Biology, Ohu University, 31-1 Tomita, Koriyama, Fukushima 963-8611, Japan
3. Minamisoma City Museum, 194 Gorai, Haramachi, Minamisoma, Fukushima 975-0051, Japan
4. Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara 252-5201, Japan