134 



MARINE ANIMALS OF MASSACHUSETTS BAY. 



Fig. ISO. 



Fig. 180. Young Sea-urchin older than Fig. 179 ; 1 1 tentacles, s&quot; s &quot; spines. 



Fig. 181. Still older Sea-urchin 5 1 1 tentacles, a anus, p pedicellaritu 5 shell one sixteenth of an inch 

 in diameter. 



