THE ISLE OF BIRDS. 199 



" There will be no trouble in getting it up," 

 said Tom, climbing into the boat; "only take 

 the bearings of the spot, and we can come back 

 for it."* 



" The two chimneys on the quarters are just 

 in line," said Long John. "If you remember 

 that, you can easily find it again." 



" Your conch is bound to be a cabin passen- 

 ger, Dick," said the doctor, as a huge mollusk, 

 which the former had brought up from the side 

 of the gun, gave a lurch and hauled its shell 

 along toward the stern with a half -leap. 



" It must be hard work traveling that way," 

 Dick remarked, pushing the conch over upon its 

 back to see its sword-like operculum. 



" Still, they make very good progress on 

 sandy bottom," replied the doctor. " The mol- 

 lusks are queer travelers. The Donax moves 

 along by sudden leaps, just as this conch does. 

 The river mussel, which you remember has the 

 curious marsupium for its young, progresses 

 by a climbing movement of its so-called foot, 



* The gun was placed in Fort Jefferson, and is probably there 

 now. AUTHOR. 

 14 



