I 70 



reaches a little beyond the first antennular article, is twice as long as broad at its base and 

 shows therefore a more slender form than the rostrum of Ar. JMartiteensis. At either side 

 of the rostrum one observes a slight rounded prominence, the trace of the supra-corneal 

 spines, which, according to the figure, are in Ar. Marutccnsis acute. 



Second antennular article one and a halfas wide as long, shorter than the visible 

 part of basal article and only half as long as the third ; stylocerite curved, acute, reaching 

 to the transverse suture of the third article. The undivided part of the outer flagellum consists 

 of 5 articles that are broader than long. Carpocerite a little longer than the antennular peduncle, 

 stout, one and a half as long as thick ; scaphocerite as long as the antennular peduncle. 



The length of the telson equals 3,5-times the width of the posterior margin, proportion 

 between the width at the base and that of the posterior margin 1,9. Spinules of the upper 

 surface small, measuring Yi; the length of the telson and placed near the lateral margins, the 

 anterior pair a little behind the middle, the proportion between the length of the telson and 

 the distance of the anterior j^air from the posterior margin being 2,3; proportion between the 

 distances of both pairs from the posterior margin 1,8. Posterior margin slightly convex, the 

 outer angles obtuse; inner longer spinules measuring one-third the width of the margin. 



The chelipeds are equal and closely resemble the small cheliped of the female of Ar. 

 Maruteensis (H. Coutieke, I.e. 1905, p. 2 i , Fig. 4, the left). The cutting-edge of the triangular 

 immobile finger is finely denticulate along its whole length, that of the tapering dactylus is entire. 



Second legs also as in Ar. Maruteetisis. Merus 3-times as long as wide. Carpus 1,12- 

 times as long as the merus, 5-times as long as thick at distal extremity; the four segments 

 are 0,42 mm., 0,14 mm., 0,14 mm. and 0,24 mm. long. Chela 0,63 mm. long, one and a half 

 as long as the first segment of the carpus, fingers half as long as the palm. 



The following legs show a somewhat less stout shape than those of Ar. Maru- 

 teensis. Relative dimensions of the third pair: merus 2; carpus i; propodus 2. The merus is 

 3,35-times as long as wide, but for the rest fully resembles that of Ar. Marideensis^ being 

 truncate at the distal extremity, with only a minute trace of an apical tooth. Carpus twice as 

 long as thick at the distal end. Propodus not 4-, but 5-times as long as wide, with 7 short 

 spinules on the posterior margin and two longer ones at the far end. 



Dactylus one-third of the propodus, of a rather stout shape, 2,6-times as long as broad 

 at its base : ventral accessory hook much shorter and smaller than the principal one. The ischium 

 appears also a little less stout than in the typical species, being one-third longer than wide distally. 



The typical species has been observed at the island of Marutea (Paumotu-islands). 



Aretopsis de Man. 

 J. G. DE Man, in: Tijdschr. d. Ned. Dierk. Vereen. (2) Dl. XI, 1910, p. 310. 



A new genus of the Alpheidae, closely related to Arete Stimps. 



Looked at from above, the rostrum appears acute, triangular, carinate, without any 

 trace of supra-corneal teeth ; in a lateral view it appears strongly compressed with the tip 

 rounded, like in the genus Athanopsis Cout. Extra-corneal teeth wanting, infra-corneal teeth 

 (outer angles of the orbits) acute, dentiform. Eyes as in the genus Arete, cornea antero-lateral, 



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