Two new species of Platythelphusa A. Milne-Edwards, 1887 (Decapoda, Potamoidea, Platythelphusidae) and comments on the taxonomic position of P. denticuiata Capart, 1952 from Lake Tanganyika, east Africa. Crustaceana (Leiden), 77(5), May 2004: 513-532. 515 [Zoological Record Volume 141]