The ornamental design for a spashell, as shown and described.
FIG. 1 is a perspective view of a spa shell showing our new design;
FIG. 2 is another perspective view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a cross-sectional view thereof, taken along line 4-4 of FIG. 3;
FIG. 5 is a cross-sectional view thereof, taken along line 5-5 of FIG. 3;
FIG. 6 is a cross-sectional view thereof, taken along line 6-6 of FIG. 3; and,
FIG. 7 is a cross-sectional view thereof, taken along line 7-7 of FIG. 3.
The broken lines immediately adjacent the shaded areas represent the bounds of the claim, while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.