QUEENSLAND PEARLS ON BLACK-LIPPED PEARL-SHELL.
The black-lipped shell produces pearls of great value.
[Milford-on-Sea.
PEARL PRODUCED BY OPERATION ON THE ANIMAL.
The pearl produced is a solid hemispherical or "button" pearl.
Although lamp-shells are represented by comparatively few species at the present day, in the older epochs they existed in enormous abundance. It is further remarkable of this group that many species are scarcely distinguishable from their fossil ancestors. Lingula, the type last referred to, is especially notable in this respect.
CHAPTER III.
STAR-FISHES, SEA-URCHINS, ETC.