302 



BULLETIN OF THE BUREAU OF FISHERIES. 



A period of activity immediately precedes molting, during which the spiny lobster 

 crawls about with intermittent intervals of rest. During this time the anterior legs are 

 used more frequently to rub the eyes and surface of the carapace and mouth parts. The 

 fourth and fifth pairs of legs are brought over the other legs and held there momentarily 

 at irregular intervals, and sometimes in a pushing position, while the other legs are placed 

 forward as though pulling. Crawling ceases when the carapace becomes disarticulated 

 at the pleon. 



CASTING OF THE SHELL. 



The spiny lobster while molting remains in an upright position, with the three ante- 

 rior pairs of legs extended forward and the fourth and fifth pairs of legs extended some 

 what backward, the dactyls apparently gripping the ground. This position was observed 

 in at least seven instances while molting took place (Fig. 272). 



Fig. 272. — Newly molted shell of spiny lobster, Panulirus argus, showing position at instant of molting. X 0.5 approximately. 



The posterior rim of the carapace begins to rise as soon as it is separated from the 

 pleon and crawling has stopped. No violent movements are made at this time, and 

 the old carapace slowly rises as the cephalothorax is withdrawn from the old shell. 

 The cephalothorax is elevated until the eyes and bases of the antenna? are on a level 

 with the posterior rim of the old carapace, which is at an angle of about 75 ° with the 

 ground. The critical time has now arrived, and the antennae are moved upward, down- 

 ward, and to both sides as the flagellar are withdrawn. The cephalothorax and legs 

 are freed by a lunge backward, and the shell is cast from the tail by a few movements. 



THE NEWLY MOLTED SPINY LOBSTER. 



The appearance of the newly molted spiny lobster is much the same as the old 

 shell in details, but the colors are fresher and brighter, and the appendages which were 



