No. 6(I92I) COMMON MOLLUSCS OF SOUTH INDIA 215 



Notes. — Chank shells {Turbinella pirum) are used in certain of the 

 islands as trumpets when the people are summoned for any work of import- 

 ance to the community, as at the launching or beaching of boats and at 

 their periodical rat hunts. Some of the fishermen aver that they occur 

 alive in the islands. This statement requires early investigation ; if true it 

 would have ? very important bearing upon the geological history of the 

 archipelago. Large Triton shells (? Triton tritoms L.) are also employed 

 largely as shell trunpets by the men, while boys often make use of Cassis 

 r«/a and some of the medium-sized Tritons; even the large frog-shell, 

 Ranella rubela, is occasionally employed. 



Pterocera chiragra. — This is very abundant and its flesh is eaten 

 extensively. The little Capulid, Hipponyx australis, is often taken adher- 

 ing to its shell. 



Fresh-water molluscs are rare. The only one found in quantity was 

 Melania tuberculata ; this occurs in all the islands, its shell thin and 

 fragile, and, prettily marbled. It is noteworthy that corrosion of the 

 apical portion which is so characteristic of Melanias of the mainland, is 

 not shown by this species under insular conditions. 



Pinna zebuensis. — This is the only species of mollusc that is looked 

 upon by the islanders as a frequent pearl-producer. It grows to a great 

 size, ths valves broadly cuneate and massive. Before the introduction of 

 the iron ramotti of European manufacture, the islanders state that single 

 valves of this shell were used by their women when digging pits in the sand 

 for the soaking of coconut husks. 



Mesodesma glabratum is probably the most abundant sand-burrowing 

 lamellibranch in the islands. It is collected extensively for food purposes. 

 Extensive beds of a species of Modiola recur at Androth ; tiny pearls are 

 occasionally obtained from this source, but too few and inferior in quality 

 to have any commercial value. 



J.H. 



