It also lacks an armed scolex unlike other "Taenia". The scolex of this worm has a cylindrical proboscis and a multitude of curved hooks. Observation of scolex help distinguish between "T. saginata", "T. solium" and "T. asiatica". The scolex bears four radially arranged suckers that surround the rostellum. The scolex also has four suckers, or a tetrad. Inside the vesicular wall is an invaginated (facing inward) scolex. Examination of the scolex or the gravid proglottids can resolve the exact species. The main nerve centre of a cestode is a cerebral ganglion in its scolex. In the larval stage the scolex is similarly shaped and is known as the protoscolex. Their scolex shows four tentacles which are covered by spines. It is composed of two main parts&colon; the vesicular wall and a scolex. The scolex attaches to the neck, or proliferative region. Larvae have six posterior hooks on the scolex (head), in contrast to the ten-hooked Cestodaria. The scolex has four suckers, but they have no hooks. The anterior end of the body is the scolex.