80 GUIDE TO THE AUSTRALIAN MUSEUM. 



The Wing Shells {StromhidcB) are the largest of the 

 Gastropods with a proboscis or non-retractile snout. They 

 do not crawl like most other Gastropods, but progress by a 

 sort of hopping movement. The Scorpion Shells, or 

 Spider Claw.s as they are sometimes called (Pterocera), 

 possess singular claw-like projections, which are developed 

 on the outer li^) of the shells. 



The Olives ( OlividcBj are common in most tropical seas, and 

 are remarkable for their beautiful polish and various 

 patterns of colouration. They burrow in sand in quest of 

 bivalves for food, and some species have the power of swim- 

 ming by expanding the lobes of the foot. 



Case V. — The Harps (Harpidce). The animals inhabiting 

 these beautiful shells are also brightly coloured, and species 

 are known from the Indo- Pacific Ocean. 



The Auger Shells ( Terebridm) are of elongate shape 

 and have a deep notch at the base of the aperture. 

 Owing to the length and comparative solidity of the shells 

 many of the species do not carry the shelly structures on 

 their backs as most do, but drag them along the sandy 

 bottom. 



The Cones {Conidce) form one of the most beautiful families 

 of shells. This group, of which about 500 distinct species 

 are known, is a great favourite with collectors on account 

 of the brilliant colours and varied 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. 

 Four species are found in Port Jackson. 



Case VI. — The Onustidce, includino; the oenera PTiorus and 

 Ojiustus, have the singular habit of cementing stones, 

 pieces of coral, and fragments of other shells to the ex- 

 terior of their shell ; hence they have been called "carrier- 

 shells," and according to the kind of material chosen, have 

 been named " Conchologists " and " Mineralogists." 



The Wentle-traps ( Scalariidce), Naticce, the Solariums or 

 Perspective Shells, and Violet Snails (lanthincd). The 

 Xaticas are mostly blind, and have a large foot, suitable 



