THE ACALEPILE. 



129 



delicate little oars are in activity, their crystalline surfaces 

 reflect the sunlight in brilliant prismatic colours, or flash in 

 the darkness with a beautiful blue light. 



The fishing apparatus of many of the ciliograde acalephse 

 is no less elegant than their locomotive organs. It consists of 

 two exceedingly slender tentacles emerging from the under 

 part of the body, which, though five or six inches long when 

 fully extended, are capable of being wholly withdrawn within 

 the body of the creature, where they are lodged in tubular 

 sheaths. On one side they are provided at regular intervals 

 with shorter and much thinner filaments, which roll together 

 spirally when the chief tentacle contracts, and expand when 

 it is stretched forth. Each of them might be compared to an 

 angle-rod, as it is armed with those urticating darts that prove 

 so formidable to many of the lower marine animals. In those 

 species which are unprovided with tentacles, such as the beroe, 

 a widely-gaping mouth supplies their place. 



The tubular acalephae differ very much from each other in 

 form, and are generally so strangely constructed that descrip- 



Diphyes Campaiiulifera. 



tion is as inadequate to give a clear idea of them, as painting 

 is to do justice to their crystalline transparency and beauty of 

 colour. Thus the diphyaB consist of two tubular pieces fitting 

 one within the other, and the stephanomia) or agalmas of a 



Agalma Okenii. 



long chain of cut diamonds, some vesicular, and others with 

 numerous appendages and tentacles. At the least shock the 



K 



