REVISION OF THE FAMILY PTEROBOTHRIIDAE PINTNER, 1931 (CESTODA, TRYPANORHYNCHA)

The trypanorhynch cestode family Pterobothriidae Pintner, 1931 is revi sed. Valid species of the genus Pterobothrium Diesing, 1850 are define d. Ten species of pterobothriid cestodes, including five new species, are described from elasmobranchs taken in waters off Australia, the In dian Ocean, the Atlantic coast of North America, and in the S Atlantic off Senegal, West Africa. Six of the species, P. acanthotruncatum, P. lintoni, P. lesteri, sp. nov., P. pearsoni, P. southwelli, sp. nov., and P. australiense, sp. nov., are described from fishes in Australian waters and the Indian Ocean. The armature of Pterobothrium heteracant hum Diesing, 1850 is redescribed using light and scanning electron mic roscopy. New intermediate hosts, locality records, and synonyms are pr ovided for P. crassicolle Diesing, 1850 from Atlantic coastal waters o f North and South America. Details of the entire armature of Pteroboth rium crassicolle Diesing, 1850 from Micropogonias furnieri (Desmarest) from Rio de Janiero are included. Two new species of Pterobothrium, P . kingstoni, sp. nov., and P. senegalense, sp. nov., are described fro m dasyatid rays in waters of the Atlantic Ocean. P. kingstoni, sp. nov ., from dasyatid rays taken in coastal waters off New England and Ches apeake Bay, Virginia, is distinguished by the presence of a wide band of hooks on the external face of the tentacle, a single row of 4 inter calary hooks, absence of a basal swelling and special armature and by a transverse base on hooks 4(4') of each principal metabasal row. Pter obothrium senegalense, sp. nov., is described from Dasyatis centroura from Goree, Senegal, West Africa, and is distinguished by 3 intercalar y rows of hooks that run over onto the external tentacular face but ne ver occupy the midline, by the size and position of hooks in the first intercalary row, and position of the first intercalary row relative t o the second and third rows. Pterobothrium southwelli, sp. nov., P. le steri, sp. nov., and P. pearsoni are described from teleosts in the In dian Ocean. P. southwelli, sp. nov., is distinguished from congeners b y a distinctive basal armature and prominent band of hooks on the exte rnal surface, a single intercalary row, uncinate hooks 1(1') in all me tabasal principal rows, and absence of dentate hooks from the metabasa l rows. P. lesteri, sp. nov., is unique in the combination of a basal row of 3 small hooks, a band of hooks, a single intercalary row of 3-4 hooks and in the possession of hooks 4(4') with dentate tips and hook s 5(5') with filamentous tips. P. pearsoni differs in possessing a ban d of hooks and 2 rows of intercalary hooks per principal row, basal ar mature restricted to the external surface, and uncinate hooks 1(1') co mbined with dentate hooks 4(4')-5(5') in all metabasal rows. Three spe cies from Australian waters, P. lintoni (MacCallum, 1916), P. australi ense, sp. nov., and P. acanthotruncatum, lack a well-developed band of hooks on the external face of the metabasal armature. P. lintoni (Mac Callum, 1916), the senior synonymn of P. malleum (MacCallum, 1916) and P. dasybati Yamaguti, 1934, is described from types and compared with new specimens from the Woods Hole region (USA) and Australia. New hos t records for adults and plerocerci of P. lintoni are reported from Au stralian waters off Queensland and South Australia. Pterobothrium chae turichthydis (Yamaguti, 1952) is considered a synonym of P. lintoni. P . australiense, sp. nov., from Pristis zijsron near Townville, Queensl and, differs from congeners in the possession of slender falcate hooks 1(1'), notched tips of hooks 5(5'), a single intercalary row of 3 hoo ks, and total absence of a band of hooks on the external tentacular fa ce. P. australiense, sp. nov., is similar to P. acanthotruncatum but h as falcate hooks at the start of each principal row, lacks the pairs o f satellite microhooks on the external face adjacent to the principal rows and possesses a band of microhooks in the basal region of the ext ernal face of the tentacle. P. acanthotruncatum is reported from new h osts in Australia and from Sri Lanka and India. A key to the 12 curren tly recognised species of pterobothriids is provided.