diff --git a/field.py b/field.py
index 1a02636..7ad0200 100644
--- a/field.py
+++ b/field.py
@@ -787,24 +787,24 @@ class Features3d:
         return
 
     @property
-    def faces(self): return np.split(self._faces,self.offset)
+    def faces(self): return np.split(self._faces,self._offset)
 
     @property
     def points(self): return self._points
 
     @property
-    def cell_areas(self): return np.split(self._cellarea,self.offset)
+    def cell_areas(self): return np.split(self._cell_areas,self._offset)
 
     @property
-    def cell_volumes(self): return np.split(self._cellvol,self.offset)
+    def cell_volumes(self): return np.split(self._cell_volumes,self._offset)
 
     def area(self,feature): 
         '''Returns the surface area of feature. If feature is None, total surface 
            area of all features is returned.'''
-        if label is None: 
+        if feature is None: 
             return np.sum(self._cell_areas)
         else: 
-            return np.sum(self.cell_areas[label-1])
+            return np.sum(self.cell_areas[feature-1])
 
     def areas(self): 
         '''Returns a tuple with surface areas of all features.'''
@@ -817,7 +817,7 @@ class Features3d:
             if self._faces is None: 
                 self.triangulate(contour_method=self.__TRI_CONTMETH,
                                  cellvol_normal_component=self.__TRI_NORMCOMP)
-            if label is None: 
+            if feature is None: 
                 return np.sum(self._cell_volumes)
             else: 
                 return np.sum(self.cell_volumes[feature-1])