No. 6 (1921) COMMON MOLLUSCS OF SOUTH LVDIA 



ITS 



the great majority are taken either by the Kadayan and Muham- 

 madan beche-de-mer divers, or accidentally in nets set for crabs, 

 whereof many miles length are shot daily during the season. The 

 shells serve a variety of purposes; as food they are broken open 

 and the flesh extracted, and used for curries; as net sinkers they 

 have the "fingers " broken off, the shell perforated and then are 

 tied at intervals along the ground rope of nets ; by burning, white- 

 wash lime is made; lastly they are used as octopus traps. To fit 

 them for the last named use, the apex of each shell is broken off 

 together with the fingers, and each is tied at the end of a short line 



Vic. S. Growth changes in the sheil of Pleroccra chiragra from the Laccadive islands. 

 In the youngest stage no fingers are present. The\' ajiptar at first as wide 

 channelled projections. 



which in turn is tied to the main rope. The branch lines are 

 attached at intervals of 5 or 6 feet along the main rope. As 

 many as 30 shells may be attached to one rope. A number of ropes 

 are tied end to end and then laid in shallow water overnight ; 

 when raised next morning a number of small octopus are found 

 sheltering in the cavities of the shells. These are used as bait when 

 lining for such fish as seer, parai, dogfish and rays. Hundreds of 

 these shell-trap lines are in use on the Ramnad coast from Devi- 

 patam northwards. In Japan and in Italy a device on the same 

 principle is used for a similar purpose ; in place of Pterocera shells, 

 the Japanese and the Italians use narrow necked vase-shaped 

 earthware pots, tied by the neck to the main line. 



Several other species are found in our seas, but none is nearly 

 so abundant as P. lambis. 



