size,
it is distinguished by a dark green coloring about the edges, and a
more or less greenish tint over the nacreous interior surface; this
color is darker in the vicinity of Jiddah and Suakin than at the
southern end of the sea, or in the Gulf of Aden. This species occurs
singly rather than congregated in beds or reefs. Although it is found
in depths of fifteen fathoms or more, most of the fishing is in less
than five fathoms of water.
The "sadof" yields pearls only rarely, and is sought principally for