The Collaborative International Dictionary
slit-shell
slit-shell \slit"-shell`\ (sl[i^]t"sh[e^]l`), n. (Zo["o]l.) Any species of Pleurotomaria, a genus of beautiful, pearly, spiral gastropod shells having a deep slit in the outer lip. Many fossil species are known, and a few living ones are found in deep water in tropical seas.
Wiktionary
slit-shell
n. Any species of (taxlink Pleurotomaria genus), a genus of pearly spiral gastropod shells having a deep slit in the outer lip. Many fossil species are known, and a few living ones are found in deep water in tropical seas.