On some anoplocephaline cestodes from pikas, Ochotona spp. (Lagomorpha), in Nepal, with the description of Ectopocephalium abei gen. et sp. n.

Three species of anoplocephaline cestodes, Anoplocephalinae gen. et sp. indet., Schizorchis d. altaica Gvozdev, 1951, and Ectopocephalium abei gen. et sp. n., are reported from pikas, Ochotona roylei (Ogilby) and O. macrotis (Gunther), from central Nepal. The taxonomic status of Schizorchis esarsi Lovekar et aI., 1972, and of Schizorchodes dipodomi Bienek and Grundmann, 1972, is discussed, with the conclusion that both species belong in the subfamily Linstowiinae, near the genus Atriotaenia Sandground, 1926. Ectopocephalium gen. n. is distinguished from other genera in the subfamily Anoplocephalinae by the modified anterior portion of the strobila, which is embedded in the tissue of the sacculus rotundus (lower ileum) of the host, and by the arrangement of the genital organs. The attachment of E. abei and the consequent tissue response are described, and the zoogeography of cestodes in pikas is briefly discussed. During March-July 1968, a biological survey of Nepal was undertaken by an expedition from the University of Hokkaido, with support of the Hokkaido University Himalayan Committee. The objectives included an investigation of the small mammals of the region, under the direction of Dr. Hisashi Abe, of Hokkaido University, who kindly made available to us a large series of preserved carcasses for parasitological examination. Information concerning the taxonomy and ecology of these mammals has been published by Abe (1971). Among the preserved materials was a series of pikas, Ochotona spp., from which we obtained anoplocephaline cestodes representing three species. One of these exhibited a combination of characters that was unlike any within the genera recognized in the subfamily Anoplocephalinae. The results of the study of these cestodes are reported in the present