176 SHELLS AND MOLLUSCOUS ANIMALS. 



kinds are the Acorn-shells, or Balani, which we see 

 on all parts of the sea-shore, or on the shores of 

 salt rivers, looking like shelly cones with the tops 

 cut off, crowding over the shells of mussels, whelks, 

 oysters, or on pieces of wood, and more or less im- 

 bedded in the substance to which they attach 

 themselves. These cones are formed of hard 

 shelly pieces, most neatly and compactly fitted 

 together, and becoming larger as the animal grows 

 older and adds to their size by periodical addi- 

 tions. A thin plate connects the cone with the 

 substance to which it adheres, and at the summit 

 is a small lid, which the animal can open or close 

 as it pleases, when it needs to put out its arms in 

 search of prey, or to withdraw them within the 

 shell. Rocks near the sea are sometimes covered 

 with these sea-acorns, and on pieces of wood drifted 

 on shore they are clustered by thousands. The 

 edges of the shells are very sharp, as those know 

 well who have ever bathed in the floating-baths 

 lying in salt rivers, when it is necessary some- 

 times to go into the water with shoes and stock- 

 ings, to escape the wounds on the feet which are 

 inflicted by them. So quickly do they encrust the 

 wood-work of these places, that it needs great care 

 and diligence in those who attend to them to keep 

 the sides and floor of the bath clear of them. 

 The lalani are called sessile barnacles, to distin- 

 guish them from the stalked barnacles, and there 

 are several species of the genus. Some kinds even 

 lodge in the coats of the whale, deeply imbedding 

 themselves in the defenceless fish ; and others fix 

 themselves on corals or sponges. We often see 

 very large foreign shells of the sea- acorn in mu- 

 seums, and these have been the homes of animals 



