Modifications in Egg of the Medusa, &c. By M.A. Giard. 249 
materials, which, rejected by the vitellus, serve in the formation of 
accessory organs of the egg, for example of the shell (a coque) or 
the vitelline membrane. Such are the hyaline vesicles of the ovum 
of Rhizostoma Cuvieri. 
Errata in the President’s Address.—At page 129, in the bottom line, for orthoclase 
read oligoclase. At page 130, in the second line from the top, for abite read albite, 
and for oligoclase read orthoclase. At page 134, in second line from bottom, omit 
the words of gypsum. 
