THE OYSTER AND THE OYSTER INDUSTRY. -37 



The only practical method of destroying the starfish so far devised 

 is by the use of the "star mop" (PL VII, fig. 1). lliis usually 

 consists of an iron bar about 10 feet long, to which are attached 8 or 

 10 large mops or brushes of heavy rope-yarn about 4 feet long. The 

 b^r moves on small wooden iron-tired wheels as it is dragged over the 

 bottom by a chain attached by three drag bars arranged as shown 

 in the figure. The chain passes through a pulley attached to a stout 

 post amidships, and the mop is raised and lowered in the same way 

 as a dredge. The starfish cling to or become entangled in the mops 

 and are brought to the surface when the apparatus is lifted. Two 

 mops are usually used, one on each side of the boat. A long narrow 

 vat is generally placed inside the gunwale on each side of the boat. 

 These vats are kept filled with water which is heated by steam from 

 the boiler circulated through pipes in the vats. Each mop with its 

 burden of "stars" is dropped into the hot water. This is the most 

 rapid and efficient method of killing the starfish and removing them 

 from the mops. Sometimes only one vat is used, placed across the 

 deck before the cabin, and each mop is swung 

 around and lowered into it by means of a small 

 crane. 



In Plate VII, figure 2, is showm a special form 

 of star mop, the "dishpan," devised for use on a 

 rocky bottom. The toboggan-shaped body con- 

 sists of two pieces of boiler iron, the larger one 4|^ 

 by 2 feet and attached to the triangular smaller 

 one by four rings bolted on as seen in the figure. 

 This allows some independence of movement of 

 the two parts. The mops are the same as used fig. z.— urosaipinxdnereus, 

 with the other form of apparatus. This mop the oyster driii of the At- 



Ti ,, 1 i^ Ti ,1 .t'- lantic coast. Natural size. 



slides over the rocks more readily than the (After Moore.) 

 wheeled bar, the brushes falling do'wTi between 

 the rocks and catching the stars. This style of mop, however, is 

 heavy and awkward to handle and is not extensively used. 



"Starring" must be kept up whenever any considerable number of 

 the enemy appears and should be of a cooperative nature. It is of 

 little avail for a planter to attempt to keep his beds free from starfish, 

 miless his neighbor does likewise. 



DRILL. 



There are at least four species of snail-like moUuscs loiown to 

 oystermen as drills or screw borers. One of these, IJrosalpinx 

 mnernis (text fig. 3), attaining a length of about an inch, is foimd 

 abundantly from Massachusetts to the east coast of Florida. The 

 eggs are laid in small, yellowish, vase-shaped, leathery capsules, *=^ 

 deposited in clusters on objects in the water. Another species is 

 Thais la'pillus, about the size of the preceding. It is fomid from the 

 east end of Long Island northward. Other species of drills (often 

 called borers, snails, whelks, or conchs) are Tliais hxmastoma (PI. 

 VIII, top) and Thais hxmastoma floridana. These sometimes reach 

 a length of 3 inches. They are found on the GuK coast, where 

 they are often very destructive to oyster beds. The eggs are laid 

 in tubular capsules about a half inch long, attached by the ends to 



o Moore, H. F. Proposed revision of "Oysters and Methods of Oyster Culture" (1S97), 



