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has been proposed (J. G. de Man, in: Archiv f. Naturg. 76. Jahrg. igio, p. 25 — 27). It 

 approaches to Ar. dorsalis Stimps., but the telson tapers more strongly, being 6,5-times as 

 long as the posterior margin is wide and the chela is 3,6-times as long as high 1 ). 



The geographical distribution of the species of this genus is the following. Arcte dorsalis 

 Stimps. was discovered near Hongkong and was collected by the "Siboga" on the Borneo. 

 bank and near the island of Saleyer, while, after Coctière, this species inhabits also the Maldive 

 Archipelago, Samoa and New Caledonia. Ar. Maruteensis Cout. has been observed in the 

 Paumotu Archipelago, while the new variety occurs in the sea between Mindanao and Halmaheira. 

 Ar. amboijiensis de Man is still only known from Amboina, Ar. indicus Cout. inhabits Hulule 

 Male Atoll (Maldive Archipelago), but occurs also in the Persian Gulf and near Djibouti. This 

 species is represented in the East Indian Archipelago by Ar. Iphianassa, which was observed 

 on the reefs of the islands of Siau and of Obi Major, Ar. Borradailei Cout., finally, inhabits 

 Hulule Male Atoll. 



The species of this genus have not yet been observed outside the Indopacific region 

 and inhabit the reefs and shallow water. 



Key to the species of the genus Arete Stimps. 



«j Supra-corneal spines present, quite conspicuous. 



Dactyli of three posterior legs simple Borradailei Cout. 



(H. COUTIÈRE, Alpheidae Mald. and Lacc. Archip. 1905, p. 861, Fig. [33). 



a„ Supra-corneal spines wanting or hardly marked. 

 Dactyli of three posterior legs biunguiculate. 

 b x Rostrum as long or almost as long as the antennular peduncle, 

 3-times as long as wide at its base. Merus of third and fourth 

 legs with a well-developed tooth. 

 c 1 Dactylus of the large chela of the male unarmed, immobile finger 

 with one acute tooth at the base. 



Propodus of third legs almost unarmed, with only 2 or 3 



spinules near the distal extremity indicus Cout. 



(H. COUTIÈRE, Alpheidae Mald. and Lacc. Archip. 1905, p. 863, Fig. 134, 135). 



e,., Dactylus of the large chela of the male with a rounded tooth 

 in the middle, immobile finger with two teeth. Propodus of 



third legs in the male with 12 spinules, in the female with 8. Iphianassa de Man 

 b. Rostrum reaching to the distal extremity of the first or the second 

 antennular article, one and a half or at most twice as long as 

 wide. Apical tooth of the merus of the third and the fourth 

 legs feebly developed or wanting. 



1) In the cited description the chela is described as being almost 5-times as long as high. This was, I suppose, the case in 

 the other cheliped which is lost; in the only cheliped now still present and which is detached from the body, the chela is 2,75 mm. long 

 (fingers included), 0,76 mm. high, and the fingers are I mm. long. 



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