103; Armstrong v. Lear, 12 Wheat. 169, 176; McKenna v. Fisk, 1 How. 241, 249.
Under these Rules, a plaintiff may proceed in the District Court for the District of Columbia against an unincorporated labor union in its common name if, by the law of the District, it has capacity to be sued as such. Only if it be decided that by the local law such a union does not have capacity to be sued in its own name need there be consideration of the second part of Rule 17 (b), which permits a suit against an unincorporated association for the enforcement of “a substantive right existing under the Constitution or laws of the United States.”
The certificate in this case discloses that the Court of Appeals is in doubt as to the meaning and application of the rule laid down in United Mine Workers v. Coronado Coal Co., 259 U. S. 344, 383-392, and the effect upon it of the second part of Rule 17 (b); cf. Brown v. United States, 276 U. S. 134, 141; Puerto Rico v. Russell & Co., 288 U. S. 476, 480-482, 483-484; Moffat Tunnel League v. United States, 289 U. S. 113, 118. But under Rules 17 and 81 of the Rules of Civil Procedure, as we have said, that question cannot arise in the present suit, unless it is first decided that under the law of the District an unincorporated labor union is without capacity to be sued in its own name. And we do not understand the certificate to seek our aid in the determination of this question of local law.
In any event, we think it appropriate that the question of local law should be answered by the courts of the District before this Court is called upon to answer it, or to consider the application and effect of the second part of Rule 17 (b) in an action in debt brought in the District of Columbia against an unincorporated labor union. There are cogent reasons why this Court should not undertake to decide questions of local law without the aid of some expression of the views of judges of the local courts