22 



SHELL GALLERY. 



Case 94. 



distinct kinds are known, is a great favourite with collectors on account 

 of the brilliant colours and various patterns of the shells. Some, owing 

 to their beauty and rarity, have been sold at very high prices, as 

 much as £50 having been paid for a single shell. The Cones are 

 found in all tropical seas, but are rare in cold or temperate latitudes. 

 None are met with on our own shores, one species alone being known 

 from the Mediterranean. They occur fossil in the Chalk and Ter- 

 tiary strata. These animals are all carnivorous, and live usually in 

 shallow water among rocks and coral-reefs. Some of them are said 

 to bite when handled, and to be dangerously poisonous, the bite in 

 some instances having been all but fatal. 



The Atlantidce, PterotracJieidce, and Garinariidce,, at various times 

 recognized as forming a distinct sub-class or order of Gastropoda, 



Pig. 15. 



Glassj' Nautilus (Carinaria lamardi). 

 a, proboscis; h, tentacles; c, shell; d, gills; e, foot; /, sucker. 



under the name of Heteropoda or Nucleobranchiata, are now regarded 

 as families of aberrant Gastropods organised for swimming in the 

 open sea. The Atlantas are found in great numbers in w^arm lati- 

 tudes, and are provided with a glassy, thin, flat, spiral shell, not 

 unlike a keeled Ammonite. The glassy shell of the Carinaria is one 

 of the most beautiful structures of any mollusc, and at one time was 

 such a rarity that £100 are said to have been given for a single 

 specimen, which at the present time is perhaps worth only from five 

 to ten pounds. Species of Carinaria are found in the Mediterranean 

 and warmer parts of the xitlantic and Indian Oceans. The animal 

 is large, semitransparent, and elongate, with a compressed fin-like 

 foot which projects from the body, and is used in swimming. The 

 gills are placed towards the hinder part of the back and covered by 

 the shell. They feed on jelly-fish of variouB kinds, and probably on 

 other soft animals. 



