Mass. Gen. Laws ch. 156 § 35
The stockholders of a corporation which reduces its capital stock in violation of section forty-five shall be liable for the payment of the debts and contracts of the corporation existing at the time of such reduction to the extent of the amount withdrawn and paid to them respectively. The stockholders of a corporation shall also be liable for all money due to operatives for services rendered within six months before demand made upon the corporation and its neglect or refusal to make such payment. A stockholder who pays on a judgment or otherwise more than his proportion of any debt included in this section shall have a claim for contribution against the other stockholders.
Unless otherwise provided in the agreement of association, articles of organization or amendments thereof, such contribution, in the case of liability based on reduction of capital stock, shall be in proportion to the amounts so withdrawn and paid to them respectively, and in the case of any other liability under this section shall be in proportion to the amounts of stock held by them respectively at the time when their liability accrued, shares of stock with par value to be computed for this purpose at their par value as fixed at that time, and shares without par value to be computed at the value, at the time of issue, of the cash, property, services or expenses for which they were issued, but not including paid-in surplus.
Mass. Gen. Laws ch. 156, § 35