PLATE XLVIII. 



Pen^id^e (Development). 



Pcnieus ; Zoea stage (p. 237). 



Penxus ; Megalopa stage, v. v. Sixth pair of pleopocla. 



Third siagnopod or first maxillipede. 



First gnathopod. 



Third pereiopod. 



Branchiae of a young Peweus. 

 3v, z, v. Rhipidura of same. 

 4. A young Penseus. 



4711. Chela of third pereiopod. 

 br. Early condition of branchial plume. 



