ESCHAllIDiE. 833 



pora is as safe on the outside of the Patella as it could 

 possibly be in the inside of the Buccinum, and this while 

 the inmate of the cserulean limpet is yet alive. 



Family ESCHAEID^. 



" I stood upon a smooth and sandy shore, — 

 'Twas one of Autumn's bright and sunny days, — 

 The sea was clear as crystal — hush'd its roar, 

 And distant mountains soften' d by the haze ; 

 Green were the waters, and the sky deep blue 

 Reflected in them form'd a lovely hue : 

 Huge porpoises were rolling o'er and o'er. 

 And fishermen were busy on the shore, 

 Mending their nets to cast into the deep, 

 That they of ocean's stores their share might reap ; 

 While dove-like mews were hovering o'er the sea, 

 Dipping their wings and feet luxuriously." — Miss S. Beever. 



Several species of the Escharidce have certain singular 

 organs attached to the cells, and called the avicularium, or 

 bird's-head, in consequence of their shape. Dr. Johnston 

 has recorded some interesting remarks made on them in 

 foreign species by Mr. Darwin ; and I am happy that I am 

 permitted to copy the following observation made on them 

 in our native species, by the Eev. T. Ilincks, of Exeter. 



'^The 'bird^s-head processes/ with which some of the 



