Hermit crab in shell of Polinices 

 heros, one of the moon shells. (Goode.) 



breathing organs extending from the back of their bodies. Howard found 

 several graceful ladder shells (Scala) in one pool, and he was the only 

 one of us who was so fortunate. In the same pool he saw a peculiar 

 shell to which he called our attention. It was a large spiral shell which 



was inhabited by a hermit crab, and its 

 surface was covered with little coral ani- 

 mals called Hydractinia. 



Professor Parker, who had gone some 

 distance ahead, now called to us, and we 

 hastened to him. As we approached we 

 saw him stooping over and looking at 

 the under side of an overhanging rock ; 

 we leaned over a small pool of water, and 

 the Professor pointed out a little bunch 

 of graceful, vase-like objects, about a 

 quarter of an inch high. These were 

 the egg capsules of the purple shell, 

 Pur pur a lapillus. 



Not far from the Purpura eggs Howard discovered several flattened 

 objects resembling the little pill bugs so common under old boards in 

 damp places. We asked Professor Parker what these were. " These," 

 replied he, " are Chitons, or coat-of-mail shells, the back being protected 

 by eight pieces instead of one, as in the other snails. If you wish to 

 preserve any of these mollusks you must tie them to a flat piece of wood 

 to keep them from rolling or coiling up." 



This spot proved a perfect mine of shells, and we collected over thirty 

 different species. The seaweed was tenanted by small dove shells 

 (Columbella) and the little Cerithites, while the sand in the little pools 

 of water contained numerous minute shells, besides some periwinkles, 

 drills, basket shells, and a few delicate bubble shells, or Bidlas. 



As the tide was now coming in very rapidly, we started toward the 

 shore. On the way George came across several living moon shells buried 

 in the sand, and near them he noticed a peculiar collarlike object made 

 of sand, to the under side of which a multitude of small, yellowish objects 

 were attached. Professor Parker said that these were the eggs of the 

 Natica, and that the collar was called a nidus. Not far away we found 

 several long strings of the flat capsules of Fulyur, and near them a large 

 living specimen which had been thrown up by the tide. Near a dead fish 

 we saw a multitude of the black basket shell, Nassa obsoleta, eating 

 its flesh. There was a perfect procession of Nassas from all directions, 

 headed toward the fish. The Professor said that the Nassas, being 



92 



