SUBROUTINE  PLTKX (Z1,ZE,Z2,NX,NY,PL)

C     [X-CROSSHATCHING]
C     ZE(NX,NY)   DATA ARRAY
C     (Z1,Z2)     INTERVAL TO BE MARKED
C     PL          PEN MOVEMENT SUBROUTINE, PERHAPS PLTCA
C     [05-JAN-75]

      EXTERNAL    PL
      DIMENSION   ZE(1)

      IX(I,J)=I+NX*(J-1)
      VI(Z)=(Z-Z1)*(Z2-Z)

      X=0.0
      Y=0.0
      DX=1.0/FLOAT(NX-1)
      DY=1.0/FLOAT(NY-1)
      DO 30 J=1,NY,2
      CALL PL (X,Y,.FALSE.)
      DO 10 I=2,NX
      I1=IX(I-1,J)
      I2=IX(I,J)
      CALL PLTIL (X,Y,VI(ZE(I1)),X+DX,Y,VI(ZE(I2)),PL)
   10 X=X+DX
      DX=-DX
      Y=Y+DY
      IF (J.GE.NY) RETURN
      CALL PL (X,Y,.FALSE.)
      DO 20 I=2,NX
      I1=IX(NX-I+2,J+1)
      I2=IX(NX-I+1,J+1)
      CALL PLTIL (X,Y,VI(ZE(I1)),X+DX,Y,VI(ZE(I2)),PL)
   20 X=X+DX
      DX=-DX
   30 Y=Y+DY
      RETURN

      END