Adult taenias are large (1-10 m long) tapeworms, so usually only representative segments are stained and mounted for identification. The scolex (upper right photo) is globular, and has four large suckers and a circle of apical hooks. A special "hook squash" preparation (upper left photo) shows the circle of hooks end-on. There is an inner and outer circles of hooks, and each hook is sickle-shaped. It is usually possible to identify a Taenia to species using only a hook squash such as this.
The lower photo shows, from top to bottom, a scolex and region of immature proglottids, two regions of mature proglottids, and a gravid proglottid. Note on the margins of the mature proglottids that the genital pores alternate irregularly along the margin. The large dark mass at the posterior of each mature proglottid is the ovary, and the field of small spots anterior to it are numerous testes. The gravid proglottid is elongate, and is filled with a large uterus that has a central stalk and numerous lateral branches, all filled with eggs. The gravid proglottids detach and pass in the feces, where they are somewhat mobile and may move a short distance from the fecal pile under their own muscular action.