VENUS MERCENARIA 25 



taken from the beds at Cold Spring. In every case the perforation 

 is near the prominence of the shell called the umbo, directly over 

 the pulpy visceral mass, which might most easily be sucked up 

 through the opening. It is a curious fact that this region of 

 the shell is selected by Lunatia for boring in any lamellibranch 

 which it attacks. It may not invariably be so, but I have many 

 shells of different species which have been drilled in this region, 

 and have happened to notice no exceptions to it. 



No matter how numerous it might be, this enemy would prob- 

 ably not be as troublesome to clam culture as the starfish is to the 

 oyster industry. In several places I have seen it collected by 

 fishermen for bait, simply by pegging a bit of fish, or even a dead 

 starfish on the bottom. In a short time numbers of them will be 

 found collected on the bait. By some such simple means, if it 

 were desirable, a clam bed probably could easily be rid of the 



creatures. 



Conclusion 



This experiment on the growth of Venus from lack of means 

 and time and favorable locality has been a limited one. In order 

 fully to demonstrate the feasibility of the artificial culture of the 

 form, it should be carried out on a very much larger scale, and 

 should be extended through a longer period of time. There can 

 be no doubt about the accuracy of the results in the case of the 

 wire cages, the growth in which has been described; and, from 

 their position, I have no reason to think that the clams were dis- 

 turbed on the other beds which have been cited as examples of 

 growth. Some of the higher beds seem to have been discovered 

 by clammers, and these were raked clean. 



The figures giving the percentages of growth, though not numer- 

 ous, at least indicate the fact that the most essential feature of the 

 culture of the little-neck clam — rapidity of growth — is all that 

 could be desired. Neither has anything appeared which would 

 suggest a natural difficulty in the way of artificial culture. 



