104 



REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



The filter cars which have been described, and in which the pre- 

 viously mentioned eggs and young fishes were kept alive, have also 

 proved themselves capable of maintaining a considerable variety of 

 other fishes and invertebrates, among which are the following: 

 Tautog, fiat fish, anchovy, oysters (both old and young), scallops, 

 anomia, crabs, barnacles, polyzoans, Botryllus, Nereis larvae, etc. 



Crabs and scallops. — On August 2, 1908, a very large number of 

 zoeae and megalops of the oyster crab were found floating at the 

 surface of the water. A considerable number were caught with a net 

 and transferred to one of the filter cars, in which they have remained 

 ever since. On September 19 their average measurements were, 

 length 8f millimeters and breadth 10^ millimeters (Mr. Sullivan). 



On August 3, thirteen scallops, measuring between 45 and 65 

 millimeters in length, were placed in the second filter car after having 

 a deep notch filed in the shell so that the rate of their growth could 

 be determined accurately. On September 18, eleven of these speci- 

 mens were caught out of the car and were in excellent condition. The 

 notch and the zone of new growth indicated precisely the size and 

 shape of the shell when the scallop was placed in the box. The in- 

 crease in length was about 20 per cent. The following table gives the 

 measurements of these specimens: 



GENERAL APPLICATION OF THE METHOD IN FISH CUL- 

 TURE. 



There are two great problems in the general question of fish culture 

 to the solution of which the method herein described contributes: 



