7 1 ]\Ir. A. Alcock on 



limits of the 30-fatliom line it would seem as if the over- 

 whelmingly muddy bottom of the Bay presented conditions 

 specially unfavourable to the existence of starfishes ; and 

 after ]>a?sin,<j this limit we usually dredpfc nothing until we 

 reach true bathj'bial conditions in the middle of the Bay. At 

 5G1 fathoms on the Andaman side, however, we have met 

 with Jh-isi'uga, and at about 500-700 fathoms, opposite to 

 the Goddvari and Kistna Deltas, on a bottom of hardening 

 clay that seems to be a special habitat for FlaheUum [japoni- 

 cinn and lacim'afum), Bathyactis^ PJwrmosonia , and Spatan- 

 goids, reniogonnster again appears. When we come to the 

 middle of the Bay, where Glohigerina-ooze, is accumulating, 

 we find forms that are familiar to deep-sea explorers all the 

 world over, namely Pararchaster^ Dytaster^ PorceUannster^ 

 Siyracaster^ UyphaJaster, Paragonaster^ Zoroaster^ ^farsi- 

 jyasfei-, IJymenaster^ and FreyeUa. 



The enclosed basin of the Andaman Sea in its moderate 

 depths appears to be peculiarly favourable to starfish life, 

 though of its greatest depths — 600 to 1200 fathoms — we 

 know nothing. The calcareous sand and ooze (coral, Glohi- 

 gerina, and Pteropod) accumulating between 200 and 300 

 fathoms seems to afford to Asteroids, as to Ophiuroids and 

 Echinoids, an optimum of development. Not only is there 

 abundance, but tliere is also variety. Though our dredgings 

 have been few, they have brought in twenty-one species, of 

 which sixteen (including three remarkable generic types) are 

 new to science. The species belong to the following genera: — 

 Pseudarchaster, Poixellanaster, Astropecten, Pentagonaster^ 

 Dorigona^ Kyniphaster (common), Anihej^oides^ Palmipeft^ 

 Chataster, Zoroaster (common), CrtbreUu, Pedicellaster^ 

 ^tolasteriaSj Brisinga, Persepliojiaster (near Plutoridster), 

 Dipsacaster (an Astropectinoid), Milteliphaster (near Calli- 

 aster)^ and iJiciynsttr (near Plectaster) . 



Concerning the Laccadive Sea our limited zoological 

 knowledge is almost entirely confined to the depths (700 to 

 1200 fathoms) in the immediate vicinity of the atolls. The 

 Gulf of Manaar may here be very naturally included. The 

 calcareous bottoms of these basins seem to be very favourable 

 to starfishes, and we have in a few hauls found representa- 

 tives of eighteen species of the following genera : — Parar- 

 chaster, Pontaster (very common), Porcellanaster^ Pentagon- 

 aster ^ Kymphaster^ Mediaster, Zoroaster (common), Brisinga. 

 and Persephonaster. 



Our observations have done but little to illustrate the 

 habits of li)e of the deej)-sea Asteroidea. Like some of the 

 common reef-forms they must sometimes live in swarms, as, 



