Geological Survey Professional Paper Volume 306, PT. 1 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. Excerpt: ...and Maury illustrated, under the name X. conchyliophora, a large specimen from the Gurabo formation. X. textilina Dall (Gardner, 1926-47, p. 561, pl. 58, figs. 31, 32, 1947), of the Chipola formation of Florida, evidently is an early form of X. delecta. It is umbilicate, but its sculpture is not as strong as that of X. delecta. The larger of the two syntypes figured by Gardner is herewith designated the lectotype. The widely umbilicate strongly sculptured fragment from the Shoal River formation, doubtfully recorded as X. textilina, is indistinguishable from X. delecta. It might, however, be the high-spired subspecies of X. delecta, X. delecta floridana Mansfield (1930, p. 121, pl. 18, figs. 5, 6), which occurs in upper Miocene deposits in western Florida. X. delecta left no descendents in the Caribbean or Panamic regions. It is closely related, however, to X. senegalensis Fischer, a Recent west African species, and its close Recent Mediterranean ally, X. crispa "Konig" Bronn, which occurs in rocks of late Miocene and Pliocene age in Italy. X. delecta has somewhat coarser sculpture than those species. The Recent Caribbean X. conchyliophora has a long history in the southeastern states and is one of the few Recent species recognized in the Eocene of that region. The Recent Panamic X. robusta Verrill, characterized by the deep orange-brown parietal callus and adjoining inner half of the interior of the body whorl, is better treated as a subspecies of conchyliophora. Occurrence: Upper part of Gatun formation (middle Miocene), eastern area, locality 173. Cercado and Gurabo formations (middle Miocene), Dominican Republic. Bowden formation (middle Miocene), Jamaica. Punta Gavilan formation (late Miocene), Falc6n, Venezuela. Family HIPPONICIDAE Genus Hipponix ...