Section 70. No person shall take from the flats or coastal waters of the commonwealth scallops other than adult scallops, or sell or offer for sale or have in possession such scallops. For the purposes of this section an adult scallop shall be a scallop with a well-defined raised annual growth line, and any scallop without such line shall be deemed a ''seed'' scallop. Scallops taken from the coastal waters shall immediately be culled when taken, and all scallops other than adult scallops shall forthwith be returned alive to the coastal waters whence taken; but it shall not be unlawful to sell or have in possession scallops other than adult scallops unavoidably left in the catch after it has been culled, to the amount of not more than five per cent of the total catch remaining. All scallops taken in accordance with this section shall be taken ashore in the shell. This and section seventy-one shall not apply to seed and adult scallops carried by storm or tide from the natural beds and deposited on beaches and flats where, in the opinion of the director, they cannot survive, but the taking of said seed scallops and the taking and sale of said adult scallops may be authorized by him at any season of the year. The director shall promulgate rules and regulations governing the taking and sale of said seed and adult scallops by special permits, which he is empowered to issue without fee, or otherwise so as to prevent the sale of seed scallops at any time, or the sale of adult scallops between April first and the following October first, except as authorized herein.