The ornamental design for a case for mobilephones, as shown and described.
1. Case for mobile phones
1.1 : Perspective
1.2 : Front
1.3 : Back
1.4 : Left
1.5 : Right
1.6 : Top
1.7 : Bottom
1.8 : Back perspective view
1.9 : Perspective view in a state of use
1.10 : Perspective view in a state of use
The broken lines depict portions of case for mobile phones that form no part of the claimed design; reproduction 1.9 is a perspective view showing the use state in which the claimed design is in a closed state; reproduction 1.10 is a perspective view showing the use state in which the claimed design has been attached to the mobile phone; this is a design for a case for mobile phones with a display on the left.