diff --git a/segpy-ext/segpy-numpy/segpy_numpy/extract.py b/segpy-ext/segpy-numpy/segpy_numpy/extract.py
index 1e9e3ce..7ccb53a 100644
--- a/segpy-ext/segpy-numpy/segpy_numpy/extract.py
+++ b/segpy-ext/segpy-numpy/segpy_numpy/extract.py
@@ -8,11 +8,6 @@ from segpy.util import ensure_superset
 from segpy_numpy.dtypes import make_dtype
 
 
-class DimensionalityError:
-    pass
-
-
-# TODO: Add inline_numbers and xline_numbers arguments
 def extract_trace_header_field_3d(reader_3d, fields, inline_numbers=None, xline_numbers=None, null=None):
     """Extract a single trace header field from all trace headers as an array.