DESCRIPTION OF THE PLATES I.-XI.; GLOSSARY AND 

 INDEX OF SUBJECTS. 



General Lellerinrj of Ilalich/sfttK avrifula J. Clark. — Througliout the memoir and in tlic plates 

 cori'espoiidiiij? parts are lettered alike, excepting in a few cases where capitals are used to indicate 

 particular regions or subdivisions. For organs and parts, or regions, of organs Greek letters are 

 used, and for minute aud microscropic portions, walls, cells, etc., italicized English letters have 

 been adopted. 



