The spectrum of singular boundary problems

A poultry drinking cup having a cup body with an input opening for engagement with a water feed line. Valve means control the flow of water through the input opening into the cup body and the cup is supported by a snap-fitting member connected to the cup. The snap-fitting member may include a cavity which is engageable with the water feed line or a support member and retaining means are provided to maintain the cavity in engagement with the water feed line or support member.