498 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Plate XVIII. 

 Metamorphosis of Alpheus, drawn by W. K. Brooks from sketches by F. H. Herrick. 



Fig. 1. Side view of tirsl or second larval stage of Alpheus heteroehelis from Nassau, drawn on 

 the night of April 15, 1887. Zeiss A. camera. / 



Fig. 2. Ventral view of the third larval stage of Alpheus heteroehelis from Nassau, drawn April 

 IS, 1887. 



Fig. .3. Ventral view of fourth larval stage of Alpheus heteroehelis from Nassau, drawn April 

 21, 1887. 



Fig. 4. First niaxilliped of the first larval stage of Alpheus minor. 



