VI PREFACE. 



in bearing testimony, and to whom my })est thanks are 

 due for the assistance afforded me, in enabhng me to 

 descril)e these curious and interesting parasitical Crus- 

 taceans. My obhgations 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. 



