Molluscs 129 



allied Apple Snails of tropical swamps 

 contrive to breathe whilst buried in the 

 mud through a long tube, the " siphon ' J 

 seen to advantage also in the common 

 whelk. These snails lay eggs in large 

 clusters on weeds high above water-mark 

 and the young, unlike those of many uni- 

 valves, pass through no larval stage, but 

 emerge complete replicas of their mother, 

 provided with minute shells. 



The Cone Shells, represented in British 

 waters by only two species, abound in 

 most tropical seas where, often very large, 

 vividly-marked and highly polished, they 

 touch the high-water mark of the shell 

 collector's ambition. Fantastic prices 

 have been paid for some of these shells, 

 especially for examples of the famous 

 " Glory of the Sea " (Conus gloria-maris). 

 In the year 1850 it was believed that 

 only two specimens of this shell were in 

 existence. It so happened that one 

 specimen was in the hands of a Dutch 



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