286 COLLECTIONS FROM MELANESIA. 



the smaller chela of the first pair of legs. In the females the 

 fingers are slender, straight, and acute, and scantily pubescent ; in the 

 males the dactyl is relatively broader, subspatulate in form ; toward 

 the distal extremity the lateral margins are closely and densely 

 fringed with hairs, which pass in an oblique line over the sides of 

 this joint, and meet on its dorsal surface immediately behind its 

 acute apex. Among the males the form of this (the smaller) chela 

 is subject to considerable variation ; sometimes (as in Dr. Heller's 

 Red-Sea specimen in the Museum collection) it is, as stated above, 

 smooth and entire, without notches or sulci, but it often exhibits a 

 gradual approach in form to the larger chela in having the upper 

 margins more or less distinctly notched, and even occasionally in 

 exhibiting traces of distinct depressions on the outer and inner sur- 

 face. As the two varieties appear to pass into one another by almost 

 insensible gradations, I have not ventured to distinguish them by 

 name. Of this latter form there are specimens from the Gulf of 

 Suez, Karachi, Samoa, and Shark Bay, West Australia (F. .17. 

 Rayner, H.M.S. ' Herald '), in the Museum collection. Among the 

 Shark-Bay specimens (preserved dry) in the Museum collection 

 one, which is apparently a female, has a slight indentation on the 

 lower margin of the smaller chela. 



Specimens from China (Gen. Hardwicke) in the Museum collection 

 are further distinguished by having a small spinule on either side of 

 the mobile finger at the distal end of the upper margin of each chela. 

 These have been designated by White A. chiragricus, M.-Edw., 

 whether rightly or not I cannot determine. 



In certain specimens I have observed that the interocular portion 

 of the rostrum is somewhat elevated and subcarinated, as in the form 

 from the Nicobars designated A. crassimanus by Heller*, which may 

 perhaps be a mere variety of A. edwardsii. Dr. Heller notes a diffe- 

 rence in the form of the smaller chelipede in A. crassimanus exactly 

 resembling that I have described above as occurring in A. edwardsii. 

 This character, I may add, seems to be alluded to by Hilgendorf f 

 in his remarks upon A. strenuus ; but if so, that author was not 

 aware of its being a mere sexual distinction, but apparently sup- 

 posed it to be a good specific character. It is also mentioned by De 

 Man, who, although regarding A. strenuus and A. crassimanus as 

 distinct species, regards the difference in the form of the smaller 

 hand as probably sexual +. 



In the British-Museum collection are specimens of what appears 

 to be a distinct but closely-allied species from the Fiji Islands, 

 Totoya {H.M.S. 'Herald'), and Sandwich Islands ( IF". H. Pease), 



S. I. Smith (;". c.) it ranges from N. Carolina southward to the Abrolhos (Brazil), 

 and Lockingcon mentions its occurrence on the Lower Californian coast and at 

 Realejo on the west coast of Nicaragua (as A. hetcrochelis) ; Dr. F. Richters 

 records it from the Mauritius. 



* Keise der Novara, Crustacea, p. 107, pi. x. fig. 2 (1865). 



t Monatsber. der Aiad. Wissensch. Berlin, p. 831 (1878). 



J ' Kotes from the Leyden Museum,' xxv. p. 105 (1881). 



