Land nemertines of Rodrigues

Two species of land nemertines have been reported from Rodrigues. The first, Geonemertes rodericana, was discovered by Gulliver in 1874 at which time extensive searches revealed no other species on the island; in 1993 two of the present authors visited Rodrigues and could find only G. pelaensis, a species which is widespread on other Indopacific islands including Rkunion, a new locality reported in the present paper. Histological re-examination of G. rodericana shows that, while the two species are closely related, both being correctly placed in the genus Geonernertes (Prosorhochmidae), they differ not only in colour but also in internal features; for example, G. pelaensis is hermaphroditic while G. rodericana is dioecious. A full description of G. rodericana is given here for the first time. Geonemertes rodericana has only been recorded from the island of Rodrigues and is now feared to be extinct.