. Bulletin of the British Museum (Natural History). 208 N. J. MORRIS & R. J. CLEEVELY slightly elevated. Calcareous operculum with few whorls in Helicotoma, but described as wedge-shaped in Polhemia and Orospira. Eccvlioptenis is open coiled. Lophonema Ulrich in Perdue & Miser, 1916 (L. Ord.), 1 = Polhemia Cullison, 1944 (L. Ord.), 1 = Orospira Butt, 1926 (L. Ord.); Helicotoma Salter, 1859 ( Ord.); Eccylioptenis RtmeM, 1888 (Sil.). Family EUOMPHALIDAE de Koninck, 1881 Round-whorled with emargination not deep and approximately in the central apical position of the whorl, but second
. Bulletin of the British Museum (Natural History). 208 N. J. MORRIS & R. J. CLEEVELY slightly elevated. Calcareous operculum with few whorls in Helicotoma, but described as wedge-shaped in Polhemia and Orospira. Eccvlioptenis is open coiled. Lophonema Ulrich in Perdue & Miser, 1916 (L. Ord.), 1 = Polhemia Cullison, 1944 (L. Ord.), 1 = Orospira Butt, 1926 (L. Ord.); Helicotoma Salter, 1859 ( Ord.); Eccylioptenis RtmeM, 1888 (Sil.). Family EUOMPHALIDAE de Koninck, 1881 Round-whorled with emargination not deep and approximately in the central apical position of the whorl, but secondarily peripheral in later forms. Occasionally ornamented with spines, or scale-like projections; conjoined and open-coiled forms; left-handed taxa not uncommon. Shell oi Euomphalus and Amphiscapha composed of an outer layer of calcite prisms and an inner layer of cross-lamelJar aragonite. Calcified operculum present in one species ofEuomphalus. We recognize three informal groups: 1. Group with conjoined or nearly joined whorls. Some Devonian species oiEuomphalus and Straparollus bear adherent peripheral shell fragments; the name Philoxene Kayser (1889) has been used for one of these species (Linsley & Yochelson 1973: 19). Maclnritella Kirk, 1927 (L. Ord.), Eiiomphalopsis Ulrich & Bridge, 1931 (L. Ord.), Poleumita Clarke & Ruedemann, 1903 (Sil.), Centrifitgus Bronn, 1834 (U. Sil.), Sinulropis Perner, 1903 (U. Sil.), Euomphalus J. Sow., 1814 ( Perm), Straparollus Montfort, 1810 (Carb.), Philoxene Kayser, 1889 (Dev.), Leptomphalus Yochelson, 1956 (Carb. - Perm.), Omphalocirrus Ryckholt, 1860 (Dev.) (left-handed), Pleuronotus Hall, 1879 (Dev.). 2. Group with open-whorled form, some bearing large spines; some others with adherent shell fragments. Serpulospira Cossmann, 1916 ( Carb.), 1 Nevadispira Yochelson, 1971 (U. Dev.), Phanerotinus J. de C. Sowerby, 1843 (L. Carb.) Sinistrospira Jhoweri, 1969 (Dev.),? Elkoceras Lintz & Lohr, 1958 (L. Carb.). 3. Lat
Size: 1575px × 1586px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
