Indian Docp-aea Dredging. 17 



observer's liaiiJ.s and surrounding objects in the vessel in 

 wliicli tlie creature was confined, but also finally communi- 

 cated a luminosity to the water itself, were poured out ajopa- 

 rcntly from below the bases of the antenna?. The Arisfceus 

 was less, and less persistently luminous in the same region. 

 'J'he WiUemoesia was luminous at two circumscribed points 

 somewhere near the orifices of the genital glands. 



In the Andaman Sea four good hauls were made. The 

 bottom to the north appears to be in general blue mud ; to 

 the south there is a good deal of green mud. From expe- 

 lience in this and previous seasons the moderate depths of 

 the Andaman Sea in its southern half appear to swarm with 

 life. Station 114 (922 fathoms) in the Andaman Sea must 

 liave a special word of notice. The trawl-bag here again 

 came on board choked with cold mud, out of which a gigantic 

 specimen of Colossendet's gigas, Hoek, was washed alive. 

 The ventral surface of the body and the ventral surfaces of 

 all the legs except the ovigcrous pair shone with a brilliant 

 blue-green metallic lustre, which died away quickly from the 

 body and part of the legs, but remained very persistently 

 along the fifth and sixth segments of all but the first pair of 

 legs. 



Crossing the Bay of Bengal from the Andamans to Madras 

 and on the continuation of the passage northwards to Bimli- 

 patam four successful hauls were carried out ; and between 

 the parallels of 11° and 12° N. a continuous line of soundings 

 was taken across the Bay. This section of the Bay shows a 

 flat plain rising very abruptly to land on either side, the 

 bottom being impure Glohigerina-ooze (except, of course, near 

 the land), with large water-worn fragments of pumice. The 

 features of the deep hauls on this line were the magnificent 

 starfishes and Holothurians. 



Considering now the results of our trawling from the bathy- 

 metric point of view, without any reference to locality, we 

 find that in the Indian seas the depths most favourable to 

 animal life are the moderate depths at 100 to 400 fathoms. 

 At this limit everywhere we find life to be varied and abun- 

 dant, the fishes and Crustaceans especially being taken in 

 swarms and in great variety. 



The following is the list of the ' Investigator ' deep-sea 

 dredging stations during the season 1890-91 : — 



Ann. d) Mag. N. Hist. Ser. 6. Vol viii. 



