496 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



PLATK XVII. 

 Metamorphosis of Alpheus, drawn from nature by W. K. Brooks. 



FIG. 1. Side view of Alpheus minor after the second molt and in the third larval stage. Zeiss 



A. 2. This larva was about ninety-five one-thousandths of an inch long from the tip 



of the rostrum to the tip of the telson. 

 FIG. 2. Dorsal view of Alpheus minor after the first molt and in the second larval stage. This 



specimen was hatched at 9 p. m., May 30, 1881, and the drawing was made at 9 a. 



m. on May 31. The specimen was eight one-hundredths of an inch long. 

 FIG. 3. Dorsal view of a young specimen of Alpheus heterochelis from Beaufort. The specimen 



was one-fifth of an inch long. It was reared from the egg in an aquarium in the 



laboratory, and it was fifteen days old when the drawing was made. It is a little 



older than those which are shown in PI. xx, Figs. 2 and 3. 



