291 



varieties discovered by the "Siboga". Aegeon cataphracta (Olivi), already known since 1792, is 

 found in the Adriatic and in the Mediterranean, has been recorded "with scarcely any doubt" 

 from Goree Island, Senegambia, and has been observed at South Africa, between Cove Rock 

 and Hood Point near East London; this species is, however, also known from the west coast 

 of the Indian peninsula and from the Ceylon Pearl Banks, while by the British Antarctic ("Terra 

 Nova") Expedition of 1910 two specimens were taken 7 miles E. of North Cape, New Zealand! 

 Mr. Stanley Kemp therefore remarks that there is reason to believe that the distribution is 

 continuous round the African coasts, but probably A. cataphracta will once prove to occur also 

 in the Indian Archipelago: in this case it would be the most widely distributed of all the 

 species of this genus. Still another form is found in the european seas, viz. A. Lacazei [Gowxx^X), 

 which, first observed in the Gulf of Marseilles, was afterwards caught on the N. side of the 

 Bay of Biscay and off the south-west of Ireland. 



All the other species occur in the Indopacific, for the genus Aegeon is not known from 



the western Atlantic nor from the west coast of America. A. rugulosa Borr. occurs at Haddu- 



mati Atoll, Maldives, but, besides this, still five other species are found off the coasts of India. 



Firstly the variety affinis Alcock of A. pctmata (Bate), which variety is distributed from the 



Red Sea, the Persian Gulf and the Arabian Sea along the west and east coasts of the peninsula 



to off Cheduba, Arakan coast, furthermore A. propensalata (Bate), recorded from the Andaman 



Sea, but also from the Key Islands and Botany Bay near Sydney, A. andamaiiensis (W.-Mas.) 



and A. bengaletisis (VV.-Mas.), known respectively from the Andaman Sea and the Bay of 



Bengal, and finally A. orientalis Hend., which occurs in the Persian Gulf, in the Gulf of 



Martaban and at Port Blair, Andamans, but which was also taken by the "Siboga" off Lirung, 



Salibabu-island. Five species and two varieties are at present known to inhabit the Indian 



Archipelago. At first A. pennata (Bate), recorded from Lobetobi Strait, .Saleh Bay (Sumbawa) 



and the Arafura Sea and, under the name of A. obsoletum Balss, also from Japan (Dzushi, 



Enoshima and Sagami Bay); another species is A. propensalata (Bate), already mentioned, which 



was taken off the Key Islands and a new variety of which was captured by the "Siboga" in 



the Bay of Bima, thirdly the new A. Sibogac from the Bali Sea with a variety ijitenncdia, 



obtained between the islands of Rotti and Timor, fourthly A. Rathbtmi, a form which was 



already known from the Hawaiian Islands and of which a male was caught by the "Siboga" 



off Pulu Kaniungan Ketjil, and finally A. orientalis Hend. from India. The seas of Japan, 



finally, are inhabited besides by A. pennata (Bate) still by another, viz. A. Habereri (Doflein), 



which is also known from the Hawaiian Islands. 



As regards the vertical range, the species of Aegeon are generally found in shallow 

 water or at moderate depth, like most other Crangonidae. The greatest depth recorded is 

 that of the new A. Rathbuni, which was captured off the Hawaiian Islands between 286 

 and 399, but also between 293 and 800 fathoms; a male of this species was, however, also 

 obtained by the "Siboga" in water of only 6 fathoms in the Strait of Makassar. Most species, 

 indeed, occur besides in shallow water also below the 100 fathom line, though they are rarely 

 found at depths greater than 300 fathoms. In his work on the Crustaceans of Nizza Risso 

 remarks that A. cataphracta is found at a depth of i 10 to 165 fathoms, but it occurs in the 



