Studies on the free-living protozoan fauna of estuaries in the coastal zone of Tamil Nadu, India Author Bindu, L. text Records of the Zoological Survey of India 2021 121 1 61 75 journal article 10.26515/rzsi/v121/i1/2021/141506 2581-8686 13186453 34. Difflugia lithophila Penard, 1902 Material examined : Mi-132, 2 ex. , Karaikkal estuary, 06.i.2013 ; Mi-138, 4 ex. , Vellar estuary, 06.xi.2015 . Diagnosis : Test sub-globular, pseudostome drawn out in the form of short collar; pseudostome circular; test covered with stony particles; test diameter 84-121 µm. Distribution in India : Chandigarh , Meghalaya , Tamil Nadu (present record), Tripura , West Bengal .