always maintained in the latching tongue 21 thereby ensuring a secure arresting action a preferred embodiment of a quadrangular panel is shown in fig3 which illustrates portion wise the production of a floor covering from panels according to the invention the panels used involve an embodiment with a first pair of edges having complementary hook profile portions h and a second pair of edges provided with complementary positively locking pivotal profile portions s the pivotal profile portions s serve to interconnect panels of differing rows of panels in this embodiment the hook profile portions h serve to interconnect panels of the same now of panels the hook profile portions h of the first pair of edges can be so designed as in the embodiment of fig1 a to 1 d alternatively the hook profile portions h of the first pair of edges can correspond to the embodiment shown in fig2 a to 2 d fig3 shows in the foremost row of panels iii a new panel 27 which is to be locked both to the previous row of panels ii and also to the adjacent panel 28 of the same row iii the new panel is fitted inclinedly in relation to the plane of the laid panels and is attached with its pivotal profile portions s to the front row.