12210070 Memoirs of the Indian Museum. Mor. VI, roro 
The foregoing is an attempt to give a reasoned account of the varieties and races 
of one of the dominant molluscs of Indian seas and to offer a working hypothesis for 
the explanation of the origin of some of the varieties which exist; at the same time to 
define and demarcate the characteristics and limits of the chief varieties, a matter 
which till now has been in a distinctly chaotic condition. 
