diff --git a/common-tools/clas-jcsg/src/main/java/org/jlab/detector/geant4/v2/MUCALGeant4Factory.java b/common-tools/clas-jcsg/src/main/java/org/jlab/detector/geant4/v2/MUCALGeant4Factory.java
index fae838ef7f..813cd1b6ed 100644
--- a/common-tools/clas-jcsg/src/main/java/org/jlab/detector/geant4/v2/MUCALGeant4Factory.java
+++ b/common-tools/clas-jcsg/src/main/java/org/jlab/detector/geant4/v2/MUCALGeant4Factory.java
@@ -4,7 +4,7 @@
 import java.util.ArrayList;
 import org.jlab.detector.volume.Geant4Basic;
 import org.jlab.detector.units.SystemOfUnits.Length;
-import org.jlab.detector.volume.G4Pgon;
+import org.jlab.detector.volume.G4Pcone;
 import org.jlab.detector.volume.G4Trd;
 import org.jlab.detector.volume.G4World;
 import org.jlab.geom.base.ConstantProvider;
@@ -24,7 +24,7 @@ public MUCALGeant4Factory(ConstantProvider provider) {
         double[] mucal_iradius = {301.0*Length.mm, 72.8*Length.mm, 81.5*Length.mm, 98.7*Length.mm};
         double[] mucal_oradius = {301.1*Length.mm, 360.6*Length.mm, 401.0*Length.mm, 98.8*Length.mm};
         double[] mucal_zpos_root = {520.0*Length.mm, 625.0*Length.mm, 696.0*Length.mm, 836.0*Length.mm};
-        G4Pgon mucalVolume = new G4Pgon("mucalVolume", phiStart, phiTotal, nplanes, nplanes, mucal_zpos_root, mucal_iradius, mucal_oradius);
+        G4Pcone mucalVolume = new G4Pcone("mucalVolume", phiStart, phiTotal, nplanes, mucal_zpos_root, mucal_iradius, mucal_oradius);
         mucalVolume.setMother(motherVolume);
         for (int sector = 1; sector <= 2; sector++) {
             List<G4Trd> layerVolume = createPanel(provider, sector, 1);
diff --git a/common-tools/clas-jcsg/src/main/java/org/jlab/detector/volume/G4Pcone.java b/common-tools/clas-jcsg/src/main/java/org/jlab/detector/volume/G4Pcone.java
new file mode 100644
index 0000000000..8808549e53
--- /dev/null
+++ b/common-tools/clas-jcsg/src/main/java/org/jlab/detector/volume/G4Pcone.java
@@ -0,0 +1,31 @@
+package org.jlab.detector.volume;
+
+import org.jlab.geometry.prim.Pcone;
+import org.jlab.detector.units.Measurement;
+import org.jlab.detector.units.SystemOfUnits.Angle;
+import org.jlab.detector.units.SystemOfUnits.Length;
+
+/**
+ * @author pdavies/devita
+ */
+// FIXME: currently support only polyheadra defintion to gemc geometry
+public class G4Pcone extends Geant4Basic {
+
+	public G4Pcone(String name, double phiStart, double phiTotal, int numZPlanes,
+                        double[] zPlane, double[] rInner, double[] rOuter ) {
+            
+              super( new Pcone(phiStart, phiTotal, numZPlanes, zPlane, rInner, rOuter));
+              setName( name );
+              setType("Polycone");
+              
+              Measurement[] dimensions = new Measurement[4+3*numZPlanes];
+              dimensions[0] = Angle.value(phiStart);
+              dimensions[1] = Angle.value(phiTotal);
+              dimensions[3] = new Measurement(numZPlanes,"counts");
+              for(int i=0; i<numZPlanes; i++) dimensions[4+0*numZPlanes+i] = Length.value(rInner[i]);
+              for(int i=0; i<numZPlanes; i++) dimensions[4+1*numZPlanes+i] = Length.value(rOuter[i]);
+              for(int i=0; i<numZPlanes; i++) dimensions[4+2*numZPlanes+i] = Length.value(zPlane[i]);
+              setDimensions(dimensions);
+        	}
+
+}
diff --git a/common-tools/clas-jcsg/src/main/java/org/jlab/geometry/prim/Pcone.java b/common-tools/clas-jcsg/src/main/java/org/jlab/geometry/prim/Pcone.java
new file mode 100644
index 0000000000..43f4aa1611
--- /dev/null
+++ b/common-tools/clas-jcsg/src/main/java/org/jlab/geometry/prim/Pcone.java
@@ -0,0 +1,61 @@
+package org.jlab.geometry.prim;
+
+import java.util.ArrayList;
+import java.util.List;
+import eu.mihosoft.vrl.v3d.Polygon;
+import eu.mihosoft.vrl.v3d.Primitive;
+import eu.mihosoft.vrl.v3d.PropertyStorage;
+
+/**
+ * @author pdavies/devita
+ */
+
+// FIXME: currently support only polyheadra defintion to gemc geometry
+public class Pcone implements Primitive {
+	
+	private final PropertyStorage properties = new PropertyStorage();
+	private int numZPlanes;
+	private double phiStart, phiTotal;
+         double[] zPlane;
+         double[] rInner;
+         double[] rOuter;	
+                     
+	public Pcone(double   phiStart,
+                     double   phiTotal,
+                     int      numZPlanes,
+                     double[] zPlane,
+                     double[] rInner,
+                     double[] rOuter)
+	{
+              if( numZPlanes < 0 || phiStart < 0 || phiTotal <= 0 ) {
+                   throw new IllegalArgumentException("Illegal arguments for Polyhedra Primitive!");
+              }
+              if( zPlane.length<2 || rInner.length<2 || rOuter.length<2) {
+                   throw new IllegalArgumentException("Illegal arguments for Polyhedra Primitive!");
+              }
+              if( zPlane.length!=rInner.length || zPlane.length!=rOuter.length) {
+                   throw new IllegalArgumentException("Illegal arguments for Polyhedra Primitive!");
+              }
+		
+              this.phiStart = phiStart;
+	      this.phiTotal = phiTotal;
+              this.zPlane = zPlane;
+              this.rInner = rInner;
+              this.rOuter = rOuter;
+	}
+
+	@Override
+	public List<Polygon> toPolygons()
+	{
+		List<Polygon> polygons = new ArrayList<>();
+        // just returns something to not cause a NullPointerException
+        return polygons;
+	}
+
+	@Override
+	public PropertyStorage getProperties()
+	{		
+		return null;
+	}
+        
+}