CHIRIDOTA-0DURBANENSIS NEW SPECIES AND A NEW RECORD OF NEOTHYONIDIUM-ARTHROPROCESSUM FROM THE EAST-COAST OF SOUTH-AFRICA (ECHINODERMATA, HOLOTHUROIDEA)

Three fragments of a new species, referable to the apodid holothuroid genus Chiridota, and two specimens and 12 fragments of a phyllophorid, referable to Neothyonidium arthroprocessum, first described by the wr iter from False Bay, Western Cape Province, are here described from sh allow water off the Bluff in Durban, KwaZulu-Natal. The new apodid, de scribed as C. durbanensis, appears to be quite close to C. furruginea (Verrill) from the north-west Atlantic waters, differing from it in th e apparent absence of wheel papillae, absence of radial muscle deposit s and the different form of tentacle deposits. Specimens of N. arthrop rocessum are much smaller than the type material and show variations i n the number and arrangement of tentacles, number of polian vesicles a nd the size of the spicules, perhaps indicating geographic and/or age variations. The characteristic U-shaped body wall deposits are here re ported, for the first time, to be accompanied by their precursors, Rat smooth buttons. The transformation of the latter to the U-shaped depo sits is discussed. The occurrence of N. arthroprocessum from the warm KwaZulu-Natal waters is a noteworthy eastward extension of a species o riginally thought not to extend beyond False Bay, Western Cape Provinc e.