. Bulletin. Science; Natural history; Natural history. A NEW SPECIES OF STRAPAROLLUS (ARCHAEOGASTROPODA) FROM THE M1SSISS1PP1AN OF NEVADA During a recent biostratigraphic study (Mount, 1972a, 1972b) of the larger invertebrates in the Up- per Paleozoic section of the central Pancake Range. Nye County, Nevada, I placed particular emphasis on the distribution of Mollusca in the Mississippian and Pennsylvanian rocks. Excluding the Cephalop- oda, mollusks of this age are poorly known in the Great Basin area of North America. In his pioneer- ing study of the Eureka district of Nevada, Walcott (1884)
. Bulletin. Science; Natural history; Natural history. A NEW SPECIES OF STRAPAROLLUS (ARCHAEOGASTROPODA) FROM THE M1SSISS1PP1AN OF NEVADA During a recent biostratigraphic study (Mount, 1972a, 1972b) of the larger invertebrates in the Up- per Paleozoic section of the central Pancake Range. Nye County, Nevada, I placed particular emphasis on the distribution of Mollusca in the Mississippian and Pennsylvanian rocks. Excluding the Cephalop- oda, mollusks of this age are poorly known in the Great Basin area of North America. In his pioneer- ing study of the Eureka district of Nevada, Walcott (1884) described several new bivalves and gastro- pods, however in later years so little attention has been given to this group that at the present lime it is virtually useless for age determination and correla- tion. Recently, the stratigraphic positions of Wal- cott's species have become better known as a result of the biostratigraphic work of Gordon (1971). It is the purpose of this paper to describe a new species of the gastropod Straparollus. Numerous fossil lists include reference to this genus, but it is generally represented by material too poorly preserved or too scanty to allow species assignment. References to the Department of Geological Sciences, University of California, Riverside, are hereafter abbreviated as UCR. Family Euomphalidae de Koninck, 1881 Genus Straparollus de Montfort, 1810 Subgenus Euomphalus Sowerby, 1812 Straparollus (Euomphalus) pancakensis, new species Figure 1 Straparollus (Euomphalus) n. sp. A: Mount, 1972b, p. 75, pi. 2, figs. 18, 19, 20. Diagnosis: Shell relatively small; whorls 5; spire slightly elevated; single high, broad, rounded spiral rib medially situated between the upper suture and outer shoulder. Description: Shell relatively small for the genus. subdiscoidal; spire slightly elevated, the first two. B Figure 1. Straparollus (Euomphalus) pancakensis. new species. Holotype UCR 7101/1. A. Top view. B. Basal view. C. Apertural view. X2. whor
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