Word not found in any official scrabble dictionaries.
"Protoconch" Definition
noun
The embryonic shell, or first chamber, of ammonites and other cephalopods.
Source: Wiktionary
The embryonal or primitive shell of an ammonoid cephalopod. owen. also called embryo-sac, oviccll, and ovisac.
Source: Century Dictionary
The apical whorl of a gastropod shell.
Source: Century Dictionary