1 20 MUNSON. [Vol. XV. 



large, level expanse of loose sand that is left entirely exposed 

 on the retreat of the tides, and receives fresh water from a stream 

 flowing into the estuary, as well as from several fresh-water 

 springs along the shore. The sand is rich in clam shells and 

 soft-bodied animals, and the abundance of organic material is 

 evidenced by the black coloration of the sand in which the 

 young Limuli live. 



At low tide they lie quietly buried, just below the surface, 

 and no tracks or markings reveal their presence. As soon as 

 the incoming tide has covered the sand, however, the Limuli 

 begin to move about, not on the surface of the sand, but just 

 beneath the surface, being always covered with the uppermost 

 layer of sand. This upper layer has the usual color of sand, 

 while just below it is black. As the little Limuli plow their 

 way along, the upper layer is pushed aside and a black track 

 appears. Immediately after the incoming tide covers the sand, 

 these black lines appear running in every direction. The 

 beginning of the black line marks the resting place of the little 

 Limulus during the absence of the tide ; the end marks the 

 distance which it has traveled. At this point it can always be 

 found. The search for these little creatures is, therefore, a 

 comparatively easy one, notwithstanding their protective color- 

 ing and their subterranean mode of locomotion. This mode of 

 locomotion is evidently useful to them as a means of protection 

 from the many enemies that infest the neighboring eelgrass. 

 Many little Limuli, departing from the path which nature has 

 marked out for them, can be seen to have fallen victims to these 

 enemies. 



Food. — One large female Limulus was found nearly buried 

 in the mud in about three feet of water. An examination 

 showed that it was enjoying its dinner, which consisted of a 

 worm. 



In Dr. Lockwood's vivid description of the habits of Limulus, 

 an instance is cited where it had been observed caught by a 

 clam, which, it was supposed, the Limulus had been trying to 

 consume. From the oyster growers at New Haven, and espe- 

 cially from Captain Barnes and his crew, it was learned that, 

 while the starfish is their dreaded foe, the horse-fish (which is 



