The ornamental design for an ellipticalpropeller, as shown and described.
FIG. 1 is a front perspective view of an elliptical propeller;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a top elevational view thereof;
FIG. 4 is a bottom elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a front plan view thereof; and,
FIG. 8 is a rear plan view thereof.
The broken lines in the drawings showing portions of the elliptical propeller are included for the purpose of illustrating environmental structure and form no part of the claimed design.