No. 6 (1921) COMMON MOLLUSCS OF SOUTH INDIA 159 



half a dozen basketsful may be sold per day during the season. 

 The demand is particularly active when fish are scarce and dear. 

 In Calicut, Beypore, Badagara and some other large towns they are 

 occasionally hawked through the streets. In other places there is 

 no regular trade ; the fisherfolk and other coast people living in 

 the neighbourhood of mussel rocks, gather supplies at low tide for 

 their own use and sometimes sell any surplus they have. 



On the East Coast, the Green Mussel is comparatively rare ; 

 nowhere is it found in thickly stocked beds as in Malabar and 

 Kanara. Yet almost everywhere along the coast occasional strag- 

 glers are found and in several estuarine backwaters where beds of 

 the edible oyster {0. virginiaua) occur, they become comparatively 

 numerous. 



In the Sonapur backwater in Ganjam district this mussel is 

 fairly abundant, considerably more so than at Pulicat. As in the 

 latter locality, its habitat is the oyster patches in the deeper parts 

 of the backwater. Particularly numerous is it in the deep main 

 channel near the fish-curing yard at Revu-Sonapur village. Here 

 occurs a deposit of large oysters living in great clustered clumps ; 

 in the angles and crevices of these masses the Green Mussels find 

 suitable lodgment. They vary from single individuals to groups 

 of three or four ; seldom do they exceed this number; they never 

 form a massive deposit nor do they ever cover their habitat with a 

 living carpet as they do in Malabar. At Sonapur they have econo- 

 mic value but not as food. Owing to certain characteristics of 

 this backwater these mussels are largely infected with the larvas 

 of parasitic worms, and, induced by the irritation thus produced, 

 pearl formation is frequent. For many years past this peculiarity 

 cf the Sonapur oysters has persisted, and those of the local fisher- 

 men who can dive, devote considerable attention to the mussel 

 fishery at times when the water in the channel is low. The pearls 

 found are modeiate in size and of poor colour, usually pinkish, but 

 as the mussels yield them fairly abundantly, the beds are well 

 exploited. 



From the observations made (which I hope to amplify shortly), 

 these pearls have a related origin to the pearls sometimes produced 

 in quantity by the common mussel {Mytilus edidis) of France and 

 England. The Sonapur backwater is the haunt of myriads of 

 seagulls and waterfowl and it is from the adult parasites contained 



