Fig. 2
Vulva of Neohelice granulata females. a Non-receptive female characterized for the presence of an opercula (o) and a smooth membrane (sm). Note the setae in the tip of the opercula (arrows). b Detailed view of simple conical setae with infracuticular insertion. Note that the tip of the setae on the picture was broken off. c Detailed view of two simple conical setae covered and surrounded by secretions. d Receptive female with mobile opercula. Note the opercula (o) and a wrinkled membrane (wm) allowing the opercula mobility, which could be displaced backwards by the male gonopod insertion during copulation (represented by an arrow)