An echinostome cercaria (? Cercaria spinifera La Valette, 1855) with 37 collar spines and paraoesophageal glands has been recorded for the first time in Britain from the gastropod Planorbarius corneus. The cercariae penetrate into and encyst in planarians. Observations made on cercariae during penetration indicate that the paraoesophageal glands are used to enter the body of the planarian and that the so-called penetration glands have some other function. Gastropod molluscs may also serve as second intermediate hosts, but there is evidence to indicate that anatomically similar cercariae from different host individuals vary in their second intermediate host preferences.

The predatory behaviour of the terrestrial planarian Microplana termitophaga has been studied by a series of long-term observations, video records and photographs. The planarians feed by ‘fishing’ for termites at the open vent of the mound of Odontotermes transvaalensis, mainly for 2 or 3 hours after dawn. Locomotion (primarily by ciliary gliding) is described and a full account is given of feeding behaviour, including the stalking and selection of prey, the method of capture (termites are bodily lifted out of the vent by the adhesive front end of the planarian) and the time course of feeding and digestion (typically about 6 min). The largest meal observed by one individual was of 13 termites consecutively consumed over 3 h 14 min. Large numbers of soldiers at the rim reduce the predation rate, though planarians can capture soldiers.