22 



a leg of the 3'''' pair. Ischium with two spines on the posterior margin. Merus 0,76 mm. long, 

 0,17 mm. broad, 4,5-times as long as broad; carpus 0,4 mm. long, 0,135 "^m. thick distally, 

 3-times as long as thick; propodus 0,84 mm. long, 8-times as long as broad, with 4 or 5 

 minute spinules on the posterior margin and a longer spine, nearly half as long as the dactylus, 

 at the distal extremity; dactylus 0,3 mm. long, 5-times as long as broad at base, simple; the 

 relative dimensions are therefore: merus 1,9; carpus i; propodus 2,1. 



16. Arete Iphianassa de Man. PI. Ill, Fig. 11 — 11/. 



Arete Iphianassa J. G. de Man, Siboga Exp., Monogr. 39^', Part II, Family Alpheidae, 191 1 

 (text) p. 164, 1915 (plates) PI. Ill, fig. 11, PI. IV, fig. 11^ — ii^-. 



Stat. 213. September 26 — October 26. South-Island near Saleyer. Reef, i male and i ova- 

 bearing female. 



It is witli some doubt that these two specimens are referred to Ar. Iphianassa, because 

 they show some differences from the original description : as this description, however, was 

 founded only on one male, one egg-laden female and one young specimen, the observed 

 differences may afterwards once prove to be owing to individual or to local variation, while 

 they are of too little importance to justify the creation of a new species. 



The male is 8,6 mm. long from tip of rostrum to tip of telson, while the female appears 

 as long as the type specimens that measured 9,5 mm. The carapace of the male, measured 

 from the orbital to the posterior margin, is 2,72 mm. long, the abdomen 5 mm., while the 

 rostrum, measured in a horizontal plane, proves to be 0,88 mm. long. The rostrum, that 

 reaches almost to the distal extremity of the antennular peduncle, is 3,6-times as long as wide 

 at the middle of the eyes; from the acute apex the lateral margins diverge straight backward 

 to just behind the anterior border of the eyes, then they run parallel and finally curve into 

 the orbital margin; the rostrum, that is slightly directed downward, resembles that of the type 

 (J. G. DE Man, I.e. fig. 11), but extends to just beyond the apex of the stylocerite. The 

 rostrura of the female (Fig. 11) is as long as in the male, al.so slightly directed downward, but the 

 straight lateral margins diverge from the apex almost to the base, running not 

 parallel at the level of the eyes. The spine at the outer angle of the orbits projects 

 distinctly beyond the eyes, both in the male and in the female, by one-third its length. 



The telson of the male is 1,06 mm. long, 4,4-times as long as the posterior margin 

 is wide, while the width at the base, 0,65 mm., is 2,7-times as broad as the posterior margin. 

 The fused part of the outer antennular flagellum is composed in the male (Fig. i i c) of f o u r 

 segments, of which the i^' and 2^^ are equal and nearly as long as wide distally, the 3"' and 

 4''> also equal, but about one and a half as long as wide; in the female (Fig. \\ d) the 

 1^' segment is one and a half as long as wide distally, the 2"'^ is half as long as the i*' and 

 a little wider than long, the 3'''^ and the 4''' are equal and nearly of the .same size and shape 

 as the i^'. In Arete indicus Cout. the fused part is composed of six segments which, according 

 to the figure, should be nearly equal and broader than long (H. CouTii-n^i:, Alpheidae Maid, and 

 Laccad. Archip. 1905, p. 864, fig. 134a). 



