Syndesmis longicanalis sp. nov., an umagillid turbellarian (Plathelminthes) from echinoids from the Kenyan coast.

A new species of umagillid rhabdocoel is described from echinoids from the Kenyan coast. Syndesmis longicanalis sp. nov. is found in the intestine of both Tripneustes gratilla and Toxopneustes pileolus collected near Mombasa. The most striking characteristic, which distinguishes this new species from all known species of the Syndesmis-Syndisyrinx group is the very long sclerotic bursal canal and the three ventral glandular papillae. A more detailed comparison between the specimens from the two different hosts demonstrates that they belong to the same species although some differences are statistically significant.