The Journal of the Indian Archipelago. 273 



a rotatory manner, others alternately raising and sinking in the water 

 or sporting over its surface. On a closer examination these grains 

 were seen to be in reality shells, some hundreds in number, nearly 

 transparent, having no perceptible columella, and apparently consisting 

 of a single coil or whorl, aperture round, breadth of the shell greater 

 than the length, so that, when on a plain surface, it rested on either 

 end like a Planorbis or Nautilus : the animal effected these rapid 

 movements by the alternate contraction and expansion of its foot, 

 which was broad and expanded, and much larger than the shell, into 

 which it seemed to have no power of withdrawing it. 



" There is another small cowry occasionally found on the coast, re- 

 sembling in colour the C. adusta, but not more than half the size, 

 and less cylindrical in shape. Captain Congalton, of the H. C. Steamer 

 Hoogly, obligingly sent me one that was lately fished up in ten 

 fathoms of water near Sultan's Shoal to the westward of Singapore, the 

 shell was partially imbedded in a species of sponge, on detaching it 

 from which, I found the cavity of the spongy mass lined with the 

 young fry of the Cyprsea, differing however in several respects from 

 that of the C. olivacea ; — instead of being contained in one membra- 

 neous envelope, there were above two hundred transparent sacs, not 

 larger than grains of mustard seed, and each containing about 30 

 shells, so minute that they could not be distinguished without the aid 

 of a microscope, at a moderate computation there could not have 

 been less than six thousand young shells : the difference in size is 

 remarkable, as the Cypraea olivacea, which had the largest offspring, is 

 a much smaller shell than the one at present under consideration : in 

 this case I had not an opportunity of studying their habits, &c. as the 

 animals were dead, having been many hours out of the water ; when 

 examined under a microscope, the shape of the shell was found to 

 resemble exactly that of the young C. olivacea above described. 



" On various parts of the coast, particularly on coral banks, a con- 

 siderable number of Echini may be observed, which, (although Natu- 

 ralists have separated them from the Testaceous Mollusca) it may 

 not be out of place to mention here ; one species in particular, I 

 cannot find to have been hitherto described ; the shell is spheroidal, 

 flattened, not more than two inches in diameter, and of a dark purple 

 colour, the spines are numerous, six or eight inches long, black, very 



2 N 



