128 LOWER COASTAL ANIMALS 



The risk of broken legs, and of cuts and gashes, is considerable in such 

 places, but we faced it along with the risk of encountering poisonous 

 sea snakes and other awkward inhabitants of coral reefs. It was only 

 when we turned the coral blocks over that we saw the fauna in all its 

 wealth and variety. Hiding underneath we would find sea-urchins, star- 

 fish, and especially brittle stars, whose arms like worms would be coiled 

 round the coral branches. Here there were crabs in amazing variety, and 

 quantities of worms; cowries fell out of the cavity along with cone shells; 

 and, firmly attached among sponges and other colonizing forms of animal 

 life, were oysters and other bivalves. 



The deeper portions of coral reefs extend into a good 50 metres of 

 water, but we had no desire to risk either our ship or our gear there. On 

 various occasions, however, we saw samples of the fauna on other bot- 

 toms at corresponding depths of from 10 to 50 metres or so. These bot- 

 toms are often either of pure sand or sand mixed with clay, and they are 

 populated by a fauna characterized more than anything else by the hand- 

 some Venus family of bivalves, which range, in various species, from the 

 Arctic to the Tropics, always in this kind of locality. Here are commonly 

 found numbers of brittle stars with arms of great flexibility (Amphiura), 

 as well as many bivalves (Thyasira, Cultellus, among others), heart- 

 urchins (Echinocardium, Spatangus), many varieties of worms, and sea- 

 pens (Pennatula, Virgularia, among others). 



In the northern Bay of Bengal, at a depth of 50 metres, we trawled 

 a bottom which appeared to be pure mud but was in fact mud finely 

 mixed with sand. We found strange sea-cucumbers (Molpadida), worms, 

 and numbers of swimming crabs, mantis crabs, etc. The last-named has 

 a body the shape of a lobster's except that the forelegs are slender pre- 

 hensile organs, while on its hind part the animal has some intensely sharp 

 spines with which it delivers a sharp blow when handled. In this haul 

 we also obtained the rare sea anemone Sphenopus marsupialis, which lives 

 in a pouch-shaped tube constructed from grains of sand. This creature 

 was first described, on the basis of some of its sand tubes belonging to a 

 private Danish collection, in the 1790s, but was not identified as a sea 

 anemone, by the Danish zoologist Steenstrup, until 1856. The specimens 

 had been found at Tranquebar. Our new and valuable individuals of 

 this Danish speciality were obtained at a position slightly to the north of 

 the first discovery. 



At a similar depth in the Strait of Macassar we located a really soft 

 bed of the type found only in calm creeks and other places well beyond 

 the reach of waves and current. It is identifiable at once by its fauna, in 



