| 1. | It bears pronounced concentric ribbing around its strongly coiled exogastric shell.
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| 2. | The shell is a compressed, exogastric cyrtocone, section sub ovoid.
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| 3. | The Cyrtogomphoceratidae are endogastric, the Westonoceratidae, exogastric.
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| 4. | "Ulrichoceras " is also considered the source for the exogastric Westonoceratidae.
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| 5. | The phragmocone is rapidly expanding and strongly exogastric.
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| 6. | The shell of " Gaspocyrtoceras " is a coarsely annularted exogastric cyrtocone.
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| 7. | Both are straight shelled or slightly exogastric.
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| 8. | Other Ordovician families are the broad and beviconic Cyclostomiceratidae and exogastric Bassleroceratidae, rounding out the Ellesmeroceratina.
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| 9. | Both are strongly compressed, exogastric brevicones with the ventral side more narrowly rounded than the dorsal.
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| 10. | The shell is cyrtoconic, exogastric, more strongly curved than in " Kindleoceras ".
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