204 REPORT OF NEW JERSEY STATE MUSEUM. 



Remarks. — The range for this animal is from Provincetown, 

 in Massachusetts, south to New Jersey, though no definite 

 record has been given for our limits. It is likely that Smith's 

 record refers to Great Egg Harbor Bay. 



The most interesting account is the exhaustive memoir by 

 Holmes, which treats exclusively of this species, from which the 

 following points are gathered. It appears to be not uncommon 

 among seaw^eed near shore, especially in eel-grass. It is preyed 

 on by small jelly-fish {Gonioneinus), to which it falls an easy 

 victim. Its food consists mostly of seaweed and small bits of 

 flesh of most any animal. The swimming of the animal is 

 mainly effected by the pleopoda, though the first impulse is 

 gained by the sudden extension of the abdomen, giving the body 

 a rapid forward movement. The abdomen is then held in an 

 extended position and the pleopods, which then hang at nearly 

 right angles to the body, serve to continue the forward motion. 

 The animal is unable to walk over a plane surface, and out of 

 the water makes indifferent progress by gliding movements pro- 

 duced by alternately flexing and extending the abdomen. It 

 is incapable of leaping like the sand fleas. Its nests are tubular, 

 generally exceeding the animal somewhat in their length. They 

 are constructed upon red seaweeds, or in eel-grass, or Ulva. 

 The nest is open at both ends of uniform diameter, and bits 

 of seaweed are usually woven in. Though frequently leaving 

 the nest, it does not seem to return to its own more readily 

 than to any other, and simply enters the first unoccupied nest 

 it meets with. When established in a nest it is driven out only 

 with difficulty, and it appears to be on the alert to keep out all 

 intruders. Its instinct to remain in the nest when danger 

 threatens is in great contrast to its quickness in flight when 

 roaming about free. A new nest is made in less than an hour. 

 The male carries the female about for a considerable period, 

 and maintains his hold against efforts to dislodge him with 

 great pertinacity. The female remains remarkably passive when 

 carried about by the male. Her body is usually held quite 

 strongly flexed, the male doing the swimming for both, so that 

 the female is transported as so much dead weight. 



