E.J.L. SOULSBY Introduction 1
CHENG, THOMAS C. The Role of Parasites 2
CAMPBELL, W. C. The Role of Drugs 17
SOULSBY, E.J.L. The Role of the Host 28
BLANKESPOOR, HARVEY D. Notes on the Biology of Plagiorchis noblei Park, 1936 (Trematoda: Plagiorchiidae) 44
BROOKS, DANIEL R. Six New Species of Tetraphyllidean Cestodes, Including a New Genus, from a Marine Stingray Himantura schmardae (Werner, 1904) from Colombia 51
BROOKS, DANIEL R. AND MONTE A. MAYES. Hymenolepis asketus sp. n. (Cestoidea: Hymenolepididae) from the Short- tailed Shrew, Blarina brevicauda Say, from Nebraska 60
BROOKS, DANIEL R. AND RICHARD W. HEARD III. Parasites of the Clapper Rail, Rallus longirostris Boddaert. III. Description of Notocotylus schmidti sp. n. (Digenea: Notocotylidae) 63
TURNER, HUGH M. AND KENNETH C. CORKUM. Allocorrigia filiformis gen. et sp. n. (Trematoda: Dicrocoelidae) from the Crayfish, Procambarus clarkii (Girard, 1852) ..65
DRONEN, NORMAN O. Jr. Studies on the Population Structures of Two Species of Haematolocechus Looss, 1899 (Digenea: Plagiorchiidae) in Raniid Frogs in New Mexico 68
KRUSE , GUNTHER O.W. Some Digenetic Trematodes from Fishes of the Bering Sea with the Descriptions of Prosorhynchus mizellei sp. n. (Bucephalidae) and Pseudopecoelus nossamani sp. n. (Opecoelidae) 73
STRINGFELLOW, FRANK. Histochemical Studies of Abomasal Tissue from Calves with monospecific and Dual Species Infections of Ostertagia ostertagi and Trichostrongylus axei 76
SULLIVAN, JAMES J. Revision of the Genus Rauschiella Babero, 1951 (Digenea: Plagiorchiidae) with a Redescription of R. palmipedis (Lutz. 1928) n. comb. From Venezuelan Frogs 82
TERWEDOW, HENRY A. JR. AND GEORGE B. CRAIG JR. Development of Waltonella flexicauda, a filarial Parasite of Rana catesbeiana, in Aedes aegypti and Other culicine Mosquitoes 86
WILLIAMS, DENNIS D. Isoglaridacris chetekensis sp. n. and I. Wisconsinensis sp. n. (Cestoda: Caryophyllaeidae) from Red Cedar River, Wisconsin Catastomid Fishes 91
COOPER, C. LAWERENCE, ROBERT R. ASHMEAD AND JOHN L.CRITES. Prevelance of Certain Endoparasitic Helminths of the Yellow perch from Western Lake Erie ..96
ERNST, JOHN V. AND CHARLES H. COURTNEY. Prepatent and Patent Periods of the bovine Coccidium Eimeria subspherica Christesen, 1941, with a Redescription of the Sporulated Oocyst 97
NOVILLA, M.N., R.P. KWAPIEN AND R.S. PENEYRA. Occurrence of Canine Hepatozoonosis in the Philippines 99
OLSEN, O. WILFORD AND ROBERT E. KUNTZ. Cestodes from Rattus Fischer in Taiwan 101
PANITZ, ERIC AND CAROL A. STAHL. Anticoccidial Activity of Flutamide (Sch 13521) against Eimeria tenella 102
PENCE, DANNY B. AND STANLEY BICKEL. Helminths of Wild turkeys in West Texas 104
MINCHEW C. DOUGLAS. The Occurrence of a Coiled Metamicrocotyla macrancantha on the Gills of the Mullet, Mugil cephalus 106
PURSGLOVE, SAMUEL R. JR. Helminth parasites of White-tailed deer (Odocoileus virginianus) from New Jersey and Oklahoma 107
Anniversary Award for 1976 109
Beltsville Symposium on Biosystematics 62
Editors Note 43
In Memoriam 59
New Honorary Member 72
New Life Members 50
Reprints of Identifications of Parasitic Metazoa in Tissue Sections by M.B. Chitwood and J. R. Lichtenfels 95