diff --git a/src/obitools/ecopcr/sequence.py b/src/obitools/ecopcr/sequence.py
index bd8e4f3..e10928f 100644
--- a/src/obitools/ecopcr/sequence.py
+++ b/src/obitools/ecopcr/sequence.py
@@ -69,7 +69,7 @@ class EcoPCRDBSequenceWriter(object):
             ecoTaxonomyWriter(dbname,self._taxonomy)
             print >> sys.stderr,"Ok"
             
-        # Identifiy the next sequence file numbre 
+        # Identifiy the next sequence file number 
         if fileidx is None:
             p = re.compile(r'([0-9]{3})\.sdx')
             fileidx = max(list(int(p.search(i).group(1)) 
@@ -107,7 +107,8 @@ class EcoPCRDBSequenceWriter(object):
         
         totalSize = 4 + 20 + 4 + 4 + 4 + cptseqlength + delength
         
-        if self._taxonomy is None or 'taxid' not in seq:
+        if self._taxonomy is None or 'taxid' not in seq :
+            raise Exception("Taxonomy error: "+seq.id)
             taxon=-1
         else:
             taxon=self._taxonomy.findIndex(seq['taxid'])