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Paris, who informeel me that he regarded it as a species distinct from Bet. aequimanus Dana, 

 and he added that even in young individuals of Dana's species the front is deeply emarginate. 

 Betaeus australis Stimps. from Port Jackson is apparently also a different species. 



Alpheopsis Cout. 



Four species of this genus, all new to science, have been collected by the "Siboga". 

 Alpheopsis consobrinus closely approaches to Alph. aequalis Cout., but the pterygostomian 

 angle terminates in a small, acute tooth or spine, as in Alph. idiocarpus Cout. and Alph. 

 Chalciope de Man, while the antennular peduncle more accords with that of Alph. aequalis 

 var. triincatus Cout. Alph. Chalciope, the second of the four, also much resembles Alph. aequalis, 

 as regards the first pair of legs, but the front is trispinose and the pterygostomian angle is 

 also armed with a small, acute tooth or spine : this species therefore approaches to Alph. 

 Haugi Cout., a remarkable form at once distinguished by the first pair of legs, the fingers 

 of which are considerably shorter than the palm. Alph. Sibogae, the third, is a more different 

 species. The front is trispinose like in Alph. Haugi and the antennal region also agrees with 

 this species, but the carpocerite is slender, as long as the antennular peduncle. The chelipeds, 

 however, are equal, project straight forward and the chelae are entirely inverted, with the 

 dactylus placed quite inferiorly: like in the genus Amphibetaeus the dactylus bears a prominence, 

 that fits into a deep groove of the immobile finger. The last species, finally, Alph. Etiryone, 

 is referred with some doubt to the genus Alpheopsis, not only because the first pair of legs 

 are missingf, but also on account of the remarkable form of the telson, which resembles that of 

 the genus Parabefaeus. Unfortunately all the four species are only represented by one specimen, 

 excepting Alph. Chalciope, of which two egg-bearing females were captured. 



The geographical distribution is the following. Alph. aequalis is rather widely distributed 

 and has been observed at Djibouti, near Perim, in the Maldive Archipelago and at New 

 Caledonia; the variety truncatus Cout. was found at Goifufahendu Atoll (Maldive Archipelago). 

 Alph. fissipes Cout. and Alph. idiocarpus Cout. are only known from Providence Island near 

 Madagascar. The four species collected by the "Siboga" are the only representatives of this 

 genus known to occur in the East Indian Archipelago : Alph. cotisobrinus was captured near 

 the N. E. point of Timor, Alph. Chalciope near the island of Waigeu, Alph. Sibogae in 

 Sapeh-Strait between the islands of Sumbawa and Flores, and Alph. ? Euryoue, finally, near 

 the Karkaralong Islands. Alph. trispinosus (Stimps.) occurs at Port Jackson, but should also be 

 found on the west coast of Africa according to Coutière (in: Buil. Mus. Paris, 1906, p. 377). 

 Alph. chilensis Cout. occurs on the coast of Chili and Alph. Haugi Cout., finally, is a fresh- 

 water species, living in a small lake near the banks of the river Ogoué (French Congo), at 

 200 kilom. from the Sea ! 



Alph. consobrimis was collected at a depth of 27 — 54 m., Alph. Chalciope between 

 59 m. and 83 m., Alph. Sibogae in water of 70 m. and Alph?. Euryone on the reef at a 

 depth of 23 — 31 m. They are all inhabitants of shallow water, which is also the case with 

 the other known species. 



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