oF 
AVICULA. 
CHARACTER GENERICUS, at page 85. 
BIRDSHELL. 
GENERIC CHARACTER, at page 85. 
In the last Number, two species of the first family of 
this genus were introduced, and it was my intention to 
have given the Pearl Shell in the following plate; but it 
seemed to be a more desirable object, first to point out the 
characters of the second division of Avicula, which in ge- 
neral form bears a very near resemblance to the genus 
Margarita, although the structure of the hinge is so totally 
distinct. 
