| 31. | Rostroconchs began their life as a small, bilaterally symmetrical, univalved protoconch planktonic larva.
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| 32. | The protoconch is usually shaped like a dome, and usually shows a few spirals.
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| 33. | The protoconch is intorted ( planorboid ).
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| 34. | The solid, fusiform shell contains 13 whorls of which two are in the protoconch.
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| 35. | The blunt, smooth protoconch contains 1?to 2 lip is arcuately produced in front.
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| 36. | The smooth protoconch consists of 1?whorl.
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| 37. | The shell contains 5 whorls, of which two in the smooth, elevated protoconch.
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| 38. | The pseudorthocerids are thought to be distinct because their protoconch and septal necks are so different.
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| 39. | The protoconch consists of 1?whorls.
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| 40. | The shell is acute, except for the apex of the protoconch, which is flattened.
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