32 HISTORY OF BRITISH CRUSTACEA. 



rulens, where it has taken its station during the night, the 

 season of its chief activity, as of most other Crustacea. It 

 interested me much to see it climb ; seizing the twigs above 

 it by stretching out its long arms alternately, it dragged up 

 its body from branch to branch, mounting to the top of the 

 plant deliberately, but with ease. While watching it I was 

 strongly reminded of the Orang-otan at the Zoological Gar- 

 dens ; the manner in which each of these very dissimilar 

 animals performed the same feat was so closely alike, as to 

 create an agreeable feeling of surprise. This circumstance 

 led me to think of another ; the resemblance was not only 

 in habit, but in conformation also, viz. in the great length 

 of arm. This is obviously an adaptation for climbing in the 

 Quadrumane as well as the Crustacean ; and a few examples 

 occurred to my remembrance in which a similar structure 

 is associated with the like habit. All the Monkey tribe, 

 for instance, and the Sloths of South America, winch are 

 almost exclusively arboreal, have the anterior limbs exces- 

 sively long. Many of the Longicorns among Beetles are 

 remarkable for their developed arms, and these are essen- 

 tially tree insects. Again, among the Spiders, the per- 

 pendicular web-makers, as Epeira, Tetragnatha, etc., which 

 run to and fro on the tracery of their slender lines, like sea- 



