Rhizocephala from New Guinea : I. Sacculina carinata Kossmann and Loxothylacus kossmanni nov. spec.

In the collections brought together by Dr. L. D. Brongersma, Dr. L. B. Holthuis, and Dr. M. Boeseman, during their voyage to New Guinea and adjacent islands 1), there are a number of crabs and hermit crabs bearing Rhizocephalan parasites. Some of the Sacculinidae of this collection are dealt with in the present paper. Sacculina carinata Kossmann Material examined: No. 1333. Host Thalamita admete (Herbst), carapace breadth 18 mm; measurements of parasite 7 X 5 X 2 1/2 mm (fig. 1b). No. 1324A. Host Thalamita admete (Herbst), carapace breadth 14 mm; measurements of parasite 6 1/2 X 4 X 2 mm (fig. 1a). No. 1324B. Host Thalamita admete (Herbst), carapace breadth 10 1/2 mm; measure-ments of parasite 6 X 3 X 1 1/2 mm (fig. 1c). No. 1334. Host Thalamita admete (Herbst), carapace breadth 10 mm; measurements of parasite 6 X 3 X 1 1/2 mm (fig. 1d). No. 1330. Host Thalamita admete (Herbst), carapace breadth 10 1/2 mm; measurements of parasite 5 1/2 X 3 X 1 1/2 mm (fig. 1f). No. 1328A. Host Thalamita ? edwardsi Borradaile, carapace breadth 7 mm; meas-urements of parasite 4 X 2 1/2 X 1 mm (fig. 1e). No. 1320. Host Thalamitoides tridens (A. Milne Edwards), carapace breadth 18 mm; measurements of parasite 7 1/2 X 4 X 2 mm (fig. 1g, h). All specimens from the reef W. of Sorido, Biak Island, shallow water, January and February, 1955. Specific characters. Male genital organs in the posterior part of the body, outside the visceral mass. Vasa deferentia wide, their cavities divided by