The Moon Snail 4^ 



each capsule. By careful and repeated measurements 

 of the surfaces of sundry egg cases, I have computed 

 the total number of eggs produced by the female in a 

 single brood to be more than half a million. 



The building of the egg case is a painstaking proc- 

 ess. More often than not, the greater part of a day 

 is given to this maternal task. The capsules are glued 

 together in the mantle cavity from whence they emerge 

 in a gelatinous sheet. As fast as it is formed, however, 

 the mother covers the agglutinant surface with selected 

 grains of the sand in which she is generally half buried. 

 As the case continues to grow, she holds it close to her 

 shell. Consequently, it travels completely around her, 

 being molded into its peculiar shape by its circuitous 

 excursion. 



After the making of the case, the mother is no 

 longer concerned with her young. She has labored to 

 insure their protection during their incubation, but 

 with this her interest ends. When her task is com- 

 pleted she moves away, abandoning her brood at their 

 birthplace. 



But she has done her work well, and the eggs have 

 little need for further maternal care. For nearly a 

 month the egg case is washed here and there over the 

 sand and stones, and remains intact. Then the eggs 

 are ready to hatch. And it is not until then that the 

 egg case begins to crumble. The action of the waves 

 assists in this disintegration; thus, at the same time, 

 assisting in the liberation of the. numerous progeny. 



But what an extraordinary progeny! Here is no 

 graceful dome but a flattened spire. It is just the 

 merest fragment of a shell. Nor is there a muscular 



