MOLLUSCS I03 



molluscs that they covered their handsomely carved 

 galleons with sheet copper. Drake's famous ship the 

 Golden Hind largely met her ultimate end through the 

 efforts of this seemingly helpless mollusc. Though at 

 first glance Teredo has all the appearance of the marine 

 worm-tube, sometimes reaching many feet in length, the 

 tube is merely an adjunct to the shell proper, a duct giving 

 free access to the sea — a long distance perhaps from the 

 animal as it lies buried deep within a jetty pile. As soon 

 as the free-swimming larval Ship Worm has acquired 

 its two valved shell it attaches itself by a thread to some 

 timber and then, using its shell as a file, proceeds to 

 advance into the woodwork, lining the burrow behind it 

 with a tube of shelly material as it goes. 



A strange variant of this tube is seen in the Watering-pot 

 Shell (Brecbites). This mollusc of the Indo-Pacific Seas 

 makes a long wide tube, one end being closed with a 

 perforated lid, like the rose of a garden can, close to which 

 lies the two small valves enclosing the animal. These 

 strange shells may reach some feet in length and are found 

 buried in sand with the " rose " directed upwards. 



The Septibranchia are a small group of marine bivalves 

 having the gills modified into muscular partitions dividing 

 the mantle chamber into two portions. Only a few species 

 are represented round our shores, one of the better known 

 being the Sky-gaper (JPoromya), a small fragile shell with 

 slightly unequal valves and a long transparent foot. 



No group of molluscs has attracted such wide attention 

 or is so little understood by the general public as the 

 Cephalopods — the Octopuses, Squids, Cuttlefish, etc. They 



