294 



Proportion between the length of the two chelae 2,65. Relative dimensions of the small chela : 

 fingers i; total length 2,7; height 0,9, this chela just 3-times as long as high. The fingers 

 are comparatively shorter than in Syn. neptunus\ they are slightly enlarged laterally 

 ancl the dactylus carries some tufts of setae along its outer and inner margins, but the upper 

 face is glabrous. 



Merus of second legs 5-times as long as wide. First segment of the carpus stout, 3- 

 times as long as thick distally, shorter than the sum of the four following, the proportion 

 being 1,41; chela just as long as the four last carpal segments taken together, fingers one 

 and a half as long as the palm. 



The merus of the third legs is exactly as long as the merus of the small cheliped and 

 3,64-times as long as wide; the merus is 1,33-times longer than the propodus, which is five 

 times as long as wide and which bears seven spinules, long 0,073 — 0,088 mm. Measured from 

 the base of the anterior margin to the extremity of the ventral hook, the dactylus proves 

 to measure just one-sixth of the propodus and to be 2, 3-times as long as broad near the 

 articulation, the dactylus being of a rather stout form. Ventral hook about tvvice as long as 

 broad at its base, rejoining the posterior margin by a concave curve, whereas the anterior 

 margin of the hook is directed obliquely to the posterior margin of the dactylus. Dorsal hook 

 hardly longer than the other, of a more slender form, the two hooks nearly parallel, the notch 

 between both hooks broadly concave at the base. 



Length 10,5 mm. 



Remarks. Synalpheus neptunus (Dana) differs by the shorter lateral spine of the 

 basicerite, by the longer fingers of the small chela, by the shorter terminal spine of the 

 scaphocerite ancl, no doubt, also by other differences. 



f41. Synalpheus Antenor de Man. 



J. G. DE Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. XI, 1910, p. 293. 

 Synon.: Alplieus butnguiailatus J. G. de Man, in: Archiv für Naturg. 53. Jahrg. 1888, p. 502, 

 PI. XXI, Fig. 6, 6a. 



Stat. 154. August 14. o°7'.2N., I30°25'.5E. Off North coast of Waigeu Island. Uepth decreased 



from 83 till 59 m. during the haul. Grey muddy sand, shells and Lithothamnion. 



1 very young specimen. 

 Stat. 164. August 20. i°42'.5 S., I30°47'.5 E. Between Misool and New Guinea. 32 m. Sand, 



small stones and shells. 1 egg-bearing female. 

 Stat. 240. November 22 till December 1. Banda-anchorage. Black sand. Coral. Lithothamnion- 



bank in 18 — 36 m. 1 very young specimen. 



This species was first referred by me in 1888 to A. biunguiculatus Stimps., because 

 Stimpson's description in: Proc. Acad. Nat. Scienc. Philadelphia 1860, p. 31, was fairly well 

 in accordance with it. Ten years later, in 1898, another species, which, however, belongs to the 

 same group, was referred by Prof. Coutière to the biunguiculatus clescribed by me in 1 888 

 and with some doubt also to Stimpson's species of the same name. Stimpson's description or 

 rather diagnose is so concise and the characters which he indicates are of such a general nature, 

 that this diagnose appears to be applicable to more than one species of this group : at present 



162 



