Redescription of Hapalorhynchus reelfooti Byrd, 1939 (Digenea: Spirorchiidae) from Sternotherus odoratus (Latreille, 1801)

Hapalorhynchus reelfooti Byrd, 1939 is redescribed based on specimens collected from the type host Sternotherus odoratus, collected in Virginia and Indiana. The type specimens show evidence of severe contraction during fixation, with subsequent loss of internal integrity and stain; therefore, they could not be used in the redescription. Hapalorhynchus reelfooti is most similar to Hapalorhynchus gracilis Stunkard, 1922 in overall form; however, it differs from that species in the possession of a cirrus sac containing a small pars prostatica, and an oval versus tricornuate egg. The presence of a cirrus sac in H. reelfooti suggests a similarity to Hapalorhynchus brooksi Platt, 1988 and Hapalorhychus stunkardi Byrd, 1939; however, it differs from those species on the basis of a variety of morphometric characters. Hapalorhynchus evaginatus Byrd, 1939 was misidentified and is considered a junior synonym of Vasotrema attenuatus Stunkard, 1928.