No. 6 (1921) COMMON MOLLUSCS OF SOUTH INDIA 



139 



Pattanavar women and lads then engage in the search, from about 

 extreme low water to a depth of a couple of feet. They find the 

 shells by turning the sand over with the feet or in the case of 

 those in the uncovered sand by marking the trail made as the 

 Olive travels about. The Pattanavars boil their catch in fresh- 

 water, extract the flesh and then either use it in their curry or fry 

 it in oil. 



Fig. 25. Oliva gihhosa crawling. X i?- 



The size of these olives {O. gihhosa) runs from 50 to 60 milli- 

 metres in length. In the sea-fishing hamlets or kuppams in the 

 neighbourhood of Pulicat Lake, their shells, with those of Donax, 

 contribute no inconsiderable bulk to the kuppam kitchen middens 

 there accumulating. 



The Margincllidac are small shells akin in appearance and 

 anatomy to the olives ; MargincUa angustata is sometimes mistaken 

 for a young olive. A distinguishing character is that the outer 

 lip is thickened. 



The last family of the Rachiglossa is that of the HarP- 

 SHELLS {Harpidac), a small group of very beautifully coloured 

 shells, the polished surface decorated with prominent longitudinal 

 ribs, suggesting the strings of a harp. The body whorl is greatly 

 inflated as in Dolium (ventricose), the spire short, and the colu- 

 mella callous. The foot is very large with a semilunar fore part, 

 separated by a transverse groove ; no operculum. As is usual in 

 highly polished shells, the mantle is reflected over the back. The 

 only living specimens I have found, were in coral reef pools in the 

 Gulf of Mannar and in the Laccadives. When irritated Harpa 

 ventricosa. our local species, commits self-mutilation by severing 

 and throwing off the hinder part of its foot, 



