60 A NATURALIST ON THE "CHALLENGER." 



very beautiful. Beneath the cliffs, which are encrusted with 

 lichens and stained of various colours, often of a deep black, are 

 steep talus slopes covered with oil trees, with a few other shrubs 

 sparingly intermingled. At the bottom of the valley is a strip 

 of comparatively level land, on which are cultivated all sorts of 

 tropical fruits, pineapples, bananas, oranges, lemons, guavas and 

 cocoanuts : with cassava, sweet potatoes and sugar-cane as field 

 crops. 



All along the valley a little way up the slopes are small 

 huts, where boys are stationed, whose duty it is to keep off 

 the monkeys, which abound amongst the rocks, and the wild 

 blue rock pigeons (Cohimba Uvea) which are very numerous, and 

 were seen flying about in flocks and alighting in the road as we 

 went along. 



John Antonio said that the monkeys used their tails to pull 

 up the sugar cane and cassava with, an unlikely story, since the 

 monkeys must be some imported African species run wild. 

 I was astonished to hear that there were monkeys at all in the 

 island, and have not seen the fact mentioned in any account of 

 the place. John said that the monkeys never came out in wet 

 weather. I did not see any of them. The boys kept up a 

 constant shouting, which resounded through the valley. 



At the bottom of the valley is a small stream running rapidly 

 over the stones, like a trout stream, and everywhere very shal- 

 low. In this stream grow watercresses and several familiar 

 English water plants, and I found two ferns on the banks. Two 

 kinds of freshwater shrimps live in the stream under the stones, 

 and are very abundant, notwithstanding the shallowness of the 

 water. One is a Palsemon, a large prawn, as big as the largest 

 specimens of our common river crayfish, and with long and 

 slender biting claws. 



The other kind is a very different animal, somewhat smaller, 

 and of the genus Atya, which is distinguished by having no 

 nippers on the larger pairs of walking legs, but only simple 

 spine-like ends to them. The two front pairs of walking legs 

 have, however, most extraordinarily shaped claws at their extre- 

 mities; quite unlike any occurring in other Crustacea, except 

 the Atyidre, as will be seen from the figure. These claws or 



