|Abstract||Certain Rhizocephalan parasites of the crabs Xanthias lamarcki (H. M.|
E.), Lybia tesselata (Latr.), and Glyptoxanthus vermiculatus (Lam.) mutually so closely correspond in all their characters that undoubtedly they belong to the same species. When the characters of this species are defined it appears that these practically correspond with the characters of Sacculina carpiliae Guér.-Gan. There are slight differences, not easily to define, and consequently not fit for a distinct specific description. Provisionally, therefore, the parasites of the crabs mentioned above are regarded as belonging to Sacculina carpiliae.
The present paper contains notes on some specimens which undoubtedly belong to Sacculina carpiliae (parasites of Carpilius convexus (Rüpp.)), so that the particulars of the parasites of the crabs mentioned may be compared to those of the typical representatives of Sacculina carpiliae.
The data of the material dealt with here are: Red Sea, Dr. Jousseaume leg. (collection Paris Museum), 1 specimen on Carpilius convexus (Rüpp.), holotype of Sacculina carpiliae Guér.-Gan.
Zanzibar, Capt. F. R. Webb leg., February 1861 (collection Peabody Museum, New Haven, Conn.), 1 specimen on Carpilius convexus (Rüpp.).
Tamatave, Madagascar, W. Kaudern leg. (collection Stockholm Museum), 1 specimen on Carpilius convexus (Rüpp.).
Manin Island, C. Colm leg., 1912 (collection Munich Museum), 1 specimen on Xanthias lamarcki (H. M. E.).
Aranuka, Gilbert Islands, outer reef, S. Bock leg., November 3, 1917 (collection Stockholm Museum), 1 specimen on Lybia tesselata (Latr.).
Indian Ocean, Salmin leg. (collection Munich Museum), 1 specimen on Glyptoxanthus