Ultrastructure studies of internuncial processes (IP) in the tegument for different body zones in a cyclophyllid davaineid adult cestode, Raillietina (Fuhrmannetta) echinobothrida infecting the small intestine of country fowl, Gallus domesticus in Naihati area of West Bengal, India have been investigated. Transmission electron microscopic observation reveals that the type, distribution, diameter, and overall characteristics of the IP along the zones of the strobila differ greatly. Contrary to the existing findings the IPs in this cestode have been recorded as thin and broad type. Thin type IP is common in all the body zones except the mature proglottides. Broad type IP is not found in the gravid proglottides. This type of IP is elaborately established in the mature proglottides. Development of broad type IP has been studied for the first time. In the gravid proglottides, IPs are either in receding nature or altogether absent. The genesis of these two types of IPs has been put forward and their functions are assigned.