234 SPAWN OF TITRBINELLA RAP A. 



may have some influence in keeping up the swaying motion 

 of the spawn in the water, which is necessary for the oxyge- 

 nation of the young in the interior of the pouches. In 

 Fig. 4, Plate II, a side view is given of a separated capsule, and 

 Fig. 3 gives magnified sketches of the young shells. The 

 emhryonic development of gasteropods is a subject of great 

 interest, but being described in various standard works, it is 

 not necessary to allude to it here. The larger ovif erous sacs 

 of the Turbinella spawn contain from 8 to 10 young shells 

 each, but the smaller ones, towards the other end of the 

 specimen, are barren. In Fig. 1, Plate II, there are 30 fertile 

 sacs, and say that each of these, on an average, contains 

 6 germs : we have thus altogether 1 80 young shells in the 

 whole of the cells. Although this is a large number to be 

 produced at one birth, it is but small when compared with 

 the immense hosts of ova produced by some other gastero- 

 pods. The chank-shell is a considerable article of commerce 

 in this country, being sacred to Vishnu, and therefore used 

 by certain devotees to blow as a horn, &c. It is also cut 

 into rings, which are used as bracelets and leg ornaments by 

 Hindu women. Subsequent to the conclusion of the above 

 remarks on the spawn of the chank, I discovered in the 

 Museum two specimens of the spawn of another mollusc 

 greatly resembling that of the chank. It is labelled " Fas- 

 ciolaria, found on the coast of Madras, " and is no doubt the 

 product of some one of the species of that genus occurring 

 in the Bay of Bengal. In its general characters this spawn 

 is almost identical with that of the chank, a similarity, 

 which is accounted for by the near relationship of the two 

 genera. In one of these specimens the slender extremity of 

 the spawn terminates in a wide membranous expansion, 

 like a school-boy's " Sucker, " which is evidently intended, 

 and is well calculated to give it a very firm attachment to 

 some rock or stone at the bottom of the water. 



Gr. Bidie. 



