PLATE XLVII. 



Pen.-eid^ (Development). 



Fig. 1. Aristeus (?), in Megalopa stage (p. 241). 



Ik. First pair of pereiopoda. 



2. Aristeus (?), younger Megalopa stage (p. 239). 

 2v. Fifth somite and rhipidura. 



3. Aristeus {?), older Megalopa stage (p. 238). 

 36. First antenna. 



3d. Mandible, showing attachment of muscles. 



Sk. First pereiopod. 



