Report on the zoological collections made in the Indo-Pacific Ocean ...

286 COLLECTIONS TEOM MELANESIA.the smaller chela of the first pair of legs. In the females thefingers are slender, straight, and acute, and scantily pubescent ; in themales the dactyl is relatively broader, subspatulate in form ; towardthe distal extremity the lateral margins are closely and denselyfringed with hairs, which pass in an oblique line over the sides ofthis joint, and meet on its dorsal surface immediately behind itsacute apex. Among the males the form of this (the smaller) chelais subject to considerable variation ; sometimes (as in Dr. Heller'sKed-Sea specimen in the Museum collection) it is, as stated above,smooth and entire, without notches or sulci, but it often exhibits agradual approach in form to the larger chela in having the uppermargins more or less distinctly notched, and even occasionally inexhibiting traces of distinct depressions on the outer and inner surface.As the two varieties appear to pass into one another by almostinsensible gradations, I have not ventured to distinguish them byname. Of this latter form there are specimens from the Gulf ofSuez, Karachi, Samoa, and Shark Bay, West Australia (F. M.Rayner, H.M.S. Herald ' '), in the Museum collection. Among theShark-Bay specimens (preserved dry) in the Museum collectionone, which is apparently a female, has a slight indentation on thelower margin of the smaller chela.Specimens from China {Gm. Ha rdwicJce) in the Museum collectionare further distinguished by having a small spinule on either side ofthe mobile finger at the distal end of the upper margin of each chela.These have been designated by White A. chimgricus, M.-Edw.,whether rightly or not I cannot determine.In certain specimens I have observed that the interocular portionof the rostrum is somewhat elevated and subcarinated, as in the formfrom the Nicobars designated A. crassimanus by Heller*, wbich mayperhaps be a mere variety of A. ediuardsii. Dr. Heller notes a differencein the form of the smaller chelipede in A. crassimanus exactlyresembling that I have described above as occurring in A. echvardsii.This character, I may add, seems to be alluded to by Hilgendorf fin his remarks upon A. strenuus ; but if so, that author was notaware of its being a mere sexual distinction, but apparently supposedit to be a good specific character. It is also mentioned by DeMan, who, although regarding A. strenuus and A. crassimanus asdistinct species, regards the difference in the form of the smallerhand as probably sexual +.In the British-Museum collection are specimens of what appearsto be a distinct but closely-allied species from the Fiji Islands,Totoya {H.M.S. 'Herald '), and Sandwich Islands (W. H. Pease),S. I. Smith (t c.) it ranges from N. Carolina southward to the Abrolhos (Brazil),and Lockington mentions its occurrence on the Lower Califoruian coast and atRealejo on the west coast of Nicaragua (as A. hdcrochelis) ; Dr. F. Eichtersrecords it from the Maui'itius.* Reise der Novara, Crustacea, p. 107, pi. x. fig. 2 (1865).t Monatsber. der Akad. Wissenseh. Berhn, p. 831 (1878).J 'Notes from the Leyden Museum,' xxv. p. 105 (1881).