OYSTERS AND METHODS OF OYSTER-CULTURE. 



317 



PROTECTION FROM DRILLS. 



No metliod of proved efficiency lias yet been devised for protecting 

 oyster-beds from the inroads of the drill, but by systematic attention 

 something could, no doubt, be done to lessen its destructive efiects. 

 In culling the oysters brought up iu the dredge or tongs care should 

 be exercised to destroy the drills. Most of them, however, will pass 

 through the intervals of the ordinary oyster-dredge, and to obviate this 

 a finer bag might be used within the dredge. This could be used 

 especially iu cleaning up the beds preparatory to planting. It should 

 be remembered, in this connection, that it is possible to infect new 

 grounds with the drill by its transportation thereto with the seed. The 

 deep-water beds of Long Island Sound have of recent years suffered 

 more and more from this pest, and it is supposed that this is accounted 



Ci'T 5. — Drill-diodge open for emptying. 



for by the use of seed from the drill-infested beds in the less saline 

 inshore waters. The use of tangles for catching starfish also, no doubt, 

 aids in the distribution of the drills by dragging them from place 

 to place. 



The most promising method which has yet been proposed for catch- 

 ing this enemy is the invention of Capt. Thomas Thomas, of New Haven, 

 Conn., who has applied for letters patent thereon. It consists of a rec- 

 tangular frame of iron bars about 4 feet long, 2 feet wide, and 18 or 20 

 inches deep. The bottom, ends, and rear are covered with an iron wire 

 screen, having a mesh of about half an inch, the top and front being 

 left open. To the upper rear edge of the frame is hijiged a stout 

 wire screen of about 1-inch mesh, its length being such that it may 

 fall between the ends and its breadth being equal to the diagonal 

 of the end pieces when in place ; therefore it extends from the lower 



