265 



The frontal and the antennal regions are typical and the measurements of the telson 

 agree with those of the female from Stat. 115 (p. 264). 



Merus of second legs 6-times longer than wide as in the male from Stat. 282, but the 

 first segment of the carpus, which is almost as long as the sum of the four following and as 

 long as the chela, is 4-times longer than thick. Relative dimensions of third legs: merus 2,8; 

 carpus 1 ; propodus 2,3. Merus 4,5-times longer than wide, propodus 7-times, the latter with 

 9 spinules, long 0,066 — 0,1 17 mm. The dactylus that measures somewhat more than one-sixth 

 of the propodus, has a more slender shape than in the typical specimen from Stat. 282, being 

 2,9-times longer than wide; the ventral hook measures one-sixth the length of the dactylus, 

 the dorsal hook is one and a half as long as the other and almost one and a half as broad 

 at its base, while the angle between both hooks, which in the typical male from Stat. 282 is 

 rounded, appears in this specimen rather sharp. 



The large chela of a specimen long 10 mm. from Stat. 310 shows the following dimensions : 

 fingers i; total length 3,45; height 1,13; these dimensions are intermediate between those 

 of the specimen from Stat. 305 and those of the typical male from Stat. 282. Second legs as 

 in the specimen from Stat. 305, but the first segment of the carpus is 4, 4-times longer than 

 thick: an intermediate number again. 



Relative dimensions of the third legs: merus 2,74; carpus i; propodus 2,3. Merus 4,2- 

 times longer than wide, propodus 6,5-times; dactylus like in the specimen from Stat. 305, but 

 the dorsal hook is hardly broader at its base than the other. 



f25. Synalpheus acanthitelsonis Cout. 



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

 PI. LXXII, fig. 13. 



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

 small stones and shells. 7 specimens, none of which with eggs. 



Stat. 273. December 23 26. Anchorage off Pulu Jedan, East coast of Aru-islands. (Pearl-banks). 

 13 m. Sand and shells. 4 specimens, 3 of which with eggs. 



These specimens agree very well with the original description. In one of the specimens 

 from Stat. 164, which is 11,5 mm. long, while the others are nearly of the same size, the 

 frontal spines and the antennal region agree with Fig. 13' (Coutière, 1. c), but the orbital 

 spines, though their form is the same, are directed inward, as in Fig. 13. The slender rostrum, 

 5-times as long as wide, reaches the middle of median antennular article; the visible part of 

 first article is one and a half as long as the second and the second a little longer than the 

 third; the stylocerite extends to the 2 nd third part of median article. The lower spine of the 

 basicerite is as long as the first article and the scale of the scaphocerite reaches to the middle 

 of third article. Telson 2,1-times longer than the distance between the outer spiniform angles 

 of the posterior margin is broad; this margin agrees with Fig. 13c (1. c), but the inner spinules 

 are 0,32 mm. long, much longer than the spiniform angles, whereas in the original description 

 the latter are described as being longer than those spinules. Proportion between the greatest 

 width and the distance between the postero-lateral spiniform angles 1,86. The spinules of the 



