582 JO URN A L, BOMB A Y NA TURAL HISTOR Y SOCIETY, Vol. XII. 



charts. A deep-sea thermometer, specially constructed to withstand the 

 great pressure, is usually sent down with the sounding tube and records the 

 minimum temperature obtained. This, in the greatest depths of the Indian 

 seas, north of 6 deg, N. —a little over 2,000 fathoms — only slightly exceeds 

 freezing point. When a suitable bottom for trawling has been found, a 

 tackle hanging from the end of a derrick is attached by a slip knot to the 

 eye above the trawl, which is then raised from the deck and lowered into 

 the water by means of the tackle. On reaching the water the tackle is released 

 and the trawl, now only attached to the wire rope, is allowed to sink by 

 its own weight. When it arrives at the bottom surplus wire to the extent 

 of half to one-third the ascertained depth is paid out. From the structure 

 of the trawl it is indifferent on which side it falls. The ship now very 

 slowly steams astern, dragging the trawl along the bottom. After a suitable 

 interval the wire rope is reeled in by the winch, the trawl again hoisted on 

 deck by means of the derrick and tackle, and the contents of the net re- 

 moved. If the bottom has been stony or rocky the swabs probably will 

 contain a large assortment of animal life, but from muddy bottoms they 

 seldom contain much. On bottoms that have been ascertained to be rocky, 

 instead of the large trawl a much smaller dredge, in which the net is 

 suspended within and protected by a stout iron frame, is used. 



Off the west coast of India on two or three occasions, at about 1,000 

 fathoms, hermit-crabs inhabiting a very interesting abode have been obtained 

 by the Investigator. The usual practice of most species of these animals is, 

 of course, to thrust the soft parts of their body into an empty mollusk shell 

 into which they can withdraw entirely in case of alarm. Here, however, the 

 hermit-crab grows to a considerable size, and the supply of a correspondingly 

 large shell is scanty. It has accordingly come about that on the back of the 

 shells inhabited by the crabs grows a budding cluster of deep-sea anemones, 

 united at their base by a thick cartilaginous-like material. At first these 

 anemones are supported by the shell, but as the crab grows too Ir.rge to be 

 contained in this, the anemone grows out pari pasfiu from the mouth of the 

 shell and secretes a thin, flexible but tough horny-looking covering for the 

 crab to dwell in, at the same time gradually absorbing the shell which first 

 supported them. It finally results that large hermit-crabs are found living 

 in a spiral chamber entirely secreted and covered by a compound anemone, 

 while the shell- the original habitation— exists as a mere ghost of its former 

 self. It is small, almost invisible, thrust to the margin of the anemone, 

 partly absorbed and the remaining fragment so soft as to be easily cut with 

 a knife. A still more curious custom was observed in some hermit-crabs 

 obtained from about 100 fathoms off the west coast. These animals have 

 largely given up the practice of living in shells ; instead, they carry about 

 over their abdomens a flexible, thin, soft sheet of anemones, retaining it in 

 position by means of their third pair of claws, and on occasions drawing the 



