1. Its peristomium is small and short, covering the posterior prostomium margin. 2. Its peristomium shows a dorsal fold partly covering the prostomium . 3. The head, or prostomium , is relatively well developed, compared with other annelids. 4. The prostomium generally has a proboscis, from which the genus has got its name. 5. The prostomium has two short frontal antennae, two globular palps and five main antennae. 6. Its prostomium has cirri, with simple supraacicular chaetae and compound subacicular chaetae with serrated blades. 7. The prostomium bears eyes, two pairs of antennae and a pair of large retractile nuchal organs. 8. Its peristomium measures the same as its succeeding segments, covering the posterior half of the prostomium . 9. Its proventricle is similar in length to the prostomium , spanning 3 segments, with about 18 muscle cell rows. 10. Prostomium rectangular shaped with two lateral horns making it appear as a " T . peristomium " without chaetae.
Mobile