directing attention to the drawings , our invention will be described in more detail . it is emphasized that since the essence of this invention lies in the snap closure device , the description has been generally limited to that portion of the containers illustrated . however , several different containers embodying this invention are shown to illustrate some of the more preferable possibilities . fig1 shows a perspective view of one preferred embodiment of a hinged container in the closed position . the hinge ( not visible in this view ) is molded into the container so that the first and second members actually leave the mold connected to each other by an integral hinge . such a container is ideal for carrying a variety of foods simultaneously because of the compartmentalized second member . specifically shown are an outwardly inclined sidewall 19 of the first ( top ) member and a protruding edge or lip 7 at the extremity of said sidewall . also shown is the second ( bottom ) member having a generally flat base 1 , four outwardly inclined sidewalls 2 ( two not visible in this view ), two inwardly protruding surfaces 5 located in an outwardly inclined sidewall , a void space or slot 13 which engages the lip 7 of the first member to effect a snap closure , and a generally flat surface 21 , which is generally parallel to base 1 , which merges the inwardly protruding surface 5 with the upper edge 11 of the sidewall . a third inwardly protruding surface 9 provides a thumb grip which aides in opening the container , but this surface does not affect the functioning of the snap considerably and still be within the scope of this invention . it is preferable , however , that the surfaces have gently curving lines to prevent stresses from weakening the closure . specifically , the inwardly protruding surface may be defined as a longitudinal segment of a parabolic cylinder where the cylinder has been segmented by a plane more or less parallel to the cylinder &# 39 ; s axis , such that the intersection of the inwardly protruding surface with an imaginary plane parallel to the base 1 results in a concave line . more specifically , the inwardly protruding surface may be defined as a longitudinal segment of a circular cylinder , such that the intersection of the inwardly protruding surface with an imaginary plane parallel to the base results in a concave line . in the preferred embodiments , the radius of curvature of the circular cylinder is approximately 1 . 5 inches . the surface protrudes inwardly 0 . 30 inches at its apex and measures 1 . 5 inches across at the slot ( measured parallel to the edge of the sidewall ). the length of the protrusion depends upon the depth of the container , but typically is 1 . 5 inches . fig2 is a fragmentary bottom view of the container in fig1 showing the generally flat base 1 of the second member , three outwardly inclined sidewalls 2 , two inwardly protruding surfaces 5 extending from the base 1 to the upper edge 11 of the sidewall , the protruding lip 7 of the first member engaged by slots 13 in the inwardly protruding surfaces 5 , the generally flat surfaces 21 which merge the inwardly protruding surfaces 5 with the upper edge 11 of the sidewall . fig4 is a fragmentary section taken along line 4 -- 4 of fig2 which with fig3 illustrates the operation of the snap closure . in fig3 the lip of the first member is being pressed downward against the generally flat surface 21 . as further pressure is applied , the lip 7 will force the inwardly protruding surface 5 in sidewall 2 outward until the lip reaches the slot 13 . at this point , the sidewall snaps back to its normal position as the lip is thrust into the slot , effecting a snap closure . this closed position is illustrated in fig4 . fig5 is a fragmentary top view of the container of fig1 showing a generally flat top surface 18 of the first member , outwardly inclined sidewalls 19 , a protruding edge or lip 7 , two inwardly protruding surfaces 5 , and the upper edge 11 of the sidewalls of the second member ( bottom ). fig6 shows a perspective view of a preferred embodiment having all the elements numbered in the previous figures , except only one inwardly protruding surface 5 is used as the closure means . this container also has an integral hinge along the edge opposite the sidewall having the snap closure . this container is ideal for food items such as hamburgers , and because of its small size , only one snap closure device is necessary . for some containers such as shown in fig1 two or more snap closures are preferred . although not shown , it is within the scope of this invention to place the inwardly protruding surfaces in the corners of the container . this would be ideal for generally square containers which contain a round item such as a hamburger . such placement would provide maximum use of available space and result in a savings in materials . fig7 shows a bottom view of a container without a hinge having one snap closure on each of two opposite sidewalls of the container . fig8 shows a bottom view of a container similar to the container in fig7 except two snap closure means used on each of two opposite sidewalls . these would be necessary for larger containers having heavier loads . fig9 is a cross - sectional view along line 9 -- 9 in fig8 illustrating the snap closure as detailed in fig3 and 4 . even though this embodiment does not have a hinge , the snap closure operates in an identical manner . it will be obvious to those skilled in the art that many variations may be made in the embodiments chosen for the purpose of illustrating the present invention without departing from the scope thereof .