v: 
PREFACE. 
in bearing testimony, and to whom iny best thanks are 
due for the assistance afforded me, in enabling me to 
describe these curious and interesting parasitical Crus- 
taceans. My obligations to the other friends who have 
assisted me with specimens or information will be found 
gratefully acknowledged in the body of the work. 
W. BAIRD. 
Bayswater ; 
December 1849 . 
