THE MOUNT DESERT REGION 165 



The Miircidae furnish our most beautiful form in Thais 

 lapilliis, which favors most exposed parts of the rocky coast. 

 This little mollusc is found throughout the entire region, 

 slowly creeping about in the tide pools or feeding on the 

 barnacles which cover the boulders. Like Litorina, it is 

 presumed to be an immigrant from Great Britain, having 

 found its way across the sea by way of Iceland and Green- 

 land, and thence down the coast. Being a cold-water animal, 

 it does not extend down the Atlantic coast for any distance, 

 and even in this latitude its best development is in open, rocky 

 exposures. One rarely finds a specimen over an inch and 

 a half long, the majority being an inch and under. The color 

 runs from white through yellow, orange, and chocolate, and 

 the specimens on the eastern shore of the Island are marked 

 with bright vermillion bands and there are other bright- 

 colored colonies, as on Yellow Island, etc. On the south shore, 

 in the region of Bass Harbor Head, one does not find as many 

 bright specimens and there is a tendency for the color to grade 

 into purple. The eggs are contained in smooth vase-shaped 

 capsules with a short stalk, ranging in color from white to a 

 purple tinge and are layed in clusters either on the sheltered 

 side of rocks or under them. 



There has been some discussion as to whether or not 

 T. lapillus can attack clams and mussels by boring their 

 shells, as does Urosalpinx cinerea. After thoroughly search- 

 ing, one finds very few of the mussel shells being bored, for 

 XJ. cinerea does not occur in this Region and the mussel is 

 evidently not the natural food of T. lapillus. They can bore a 

 large-size mussel if they wish, and we have a mussel taken 

 with the animal in the act of boring it. They bore one side 

 and then go to the other side, thus showing that it is a natural 

 habit. In this Region the abundance of barnacles and other 

 food probably suflfices their needs. An examination of neck- 

 laces worn by the Cro-Magnon people of southern France 

 reveals the fact that their attractive color and shape appealed 

 to the eye a long time ago. 



