nephrotomy

[ Gr.nephros =a kidney, and Surg.: The operation of extracting a stone from the kidney by cutting. něph-thy-a, 8. [NEPHTHYS.] Zool.: A genus of Alcyonidae. The derm is a leathery skin, bristling with spicules; it forms branching lobes ending in projecting tubercles, in which are the polypi. The only known species is from the Red Sea.