Merus 3,4-times as long as wide, carpus 2,9-times as long as thick at the distal extremity 

 that bears a movable spinule; propodus 5,3-times as long as wide, the lower margin with 

 6 spinules, long 0,12 mm., besides the two at the far end; dactylus a little more than x / 4 of 

 the propodus and 3-times as long as broad at base, agreeing with the figure 35 c (1. c), but 

 the dorsal hook almost one and a half as long as the other. 



Relative dimensions of the 4 th leg: merus 1,76, carpus 1, propodus 1,65; dactylus 0,47 

 (measured from the proximal end of the anterior margin to the apex of the ventral hook). 

 Merus 3,4-times as long as wide, carpus 3-times as long as thick at the distal extremity, that 

 bears a movable spinule, propodus 5,1-times as long as wide, with 5 spinules besides the two 

 at the far end; dactylus a little more than l j i of the propodus and 2,85-times as long as wide 

 at base, resembling that of the 3 rd pair. 



Ova 0,7 — 0,8 mm. long. 



21. Synalpheus hastilicrassus Cout. var. acanthitelsoniformis de Man. PI. III, fig. 14,14a. 



Synalpheus hastilicrassus H. Coutière, Alpheidae Mald. and Laccad. Archip., 1905, p. 875, 



PI. LXXII, fig. 12— \7.d. 

 Synalpheus hastilicrassus J. G. de Man, Siboga Exp., Monogr. XXXIX a', Part II, Family 



Alpheidae, 191 1 (text) p. 263, 191 5 (plates) PI. X, fig. 45 — 450". 

 Synalpheus hastilicrassus H. Cout., var. acanthitelsoniformis J. G. de Man, in: Zoolog. Meded. 



uitgeg. vanwege 's Rijks Mus. v. Nat. Hist. te Leiden, 1920, Dl. V, Afl. 3, p. 108. 



Stat. 115. July 9/1 1. East side of Pajunga Island, Kwandang-bay. Reef. 1 male. 



Professor Coutière in his valuable dissertation of 1899, entitled Les "Alpheidae", remarks 

 p. 296, that in the genus Synalpheus the 2" d pleopods show no sexual difference and that in 

 some species the 2 nd pleopod of the male bears even no stylamblys, so e. g. in Syn. neptuntts 

 (at least some specimens), in Syu. biunguicnlatus etc, while in the female of the same species a 

 single, though well-developed stylamblys occurs. After having examined the 2 nd and the 3 rd 

 pleopod of the specimen from Kwandang-bay under the microscope, the endopodite of both 

 pleopods proved to be devoid of a stylamblys and the endopodite of the 2 nd proved to bear 

 no appendix masculina : we may therefore conclude by analogy that the specimen from 

 Stat. 115 is a male. 



The rostrum is long, slender, acute, 4 3 / 8 -times as long as broad at the level of the 

 orbital margin, reaching almost to the middle of 2 nd antennular article ; lateral spines half as 

 long as the rostrum, elongate-triangular, slender, with the acute tips slightly turned inward, 

 the tips bearing a forwardly directed seta. 



Antennular peduncle 4-times as long as the 2 nd joint is wide distally ; basal joint as long 

 as the 2 nd and 3 rd taken together, 2 nd joint a little longer than wide, 3 rd a little shorter than 

 2 nd. stylocerite as long as basal article. Basicerite truncate above, straight; lower spine 

 of basicerite a little longer than the outer margin of the basal part and a trifie longer or as 

 long as the stylocerite. Carpocerite 3-times as long as wide in the middle, distinctly narrowing 

 to the distal extremity, projecting beyond the antennular peduncle by a little more than the 

 3 rd article ; terminal spine of scaphocerite a little shorter than the carpocerite, but much longer 

 than the antennular peduncle ; scale of scaphocerite reaching to the middle of 3 rd article. 



