796 CRUSTACEA. 



Balabac Passage, off Mangsi Islands, north of Borneo; brought 

 up from a depth of thirty-one fathoms. 



Colour, dull yellow. Length, half an inch. This species attaches 

 itself to seaweeds or Corallines by means of its six hinder legs, and 

 stands like a Caprella, with the body nearly erect ; the anterior legs 

 are commonly thrown over the mouth, being used principally for 

 taking food, for which purpose they are adapted by means of their 

 ciliae, which form a kind of net for capturing prey. These four ante- 

 rior pairs are five-jointed; they gradually increase in length from the 

 first to the fourth ; and the last three pairs as gradually diminish. 

 The latter are naked or nearly so ; of the six joints, the second is 

 longer than the third or fourth ; the sixth is shorter than the fifth, 

 and has a tooth under the extremity. The head is oblong, with 

 five tubercles on the dorsal surface, and one spinous process in front 

 below. The eye is lateral and prominent. The inner antennas have 

 a few short hairs at tip. The second joint of the outer or inferior 

 antennae is stout and angular. The abdomen is very convex below. 

 The plates below are barely seen in a dorsal view projecting a little 

 on either side, near the apex. 



Leachia nodosa, Dana, Amer. J. Sci. [2], viii. 424, 1849. 



Subtribe TANAIDEA. 



Family I. TANAHLE. 



Subfamily TANAINJE. 



Genus TANAIS. 



The head in this genus is very short, and often appears as if sol- 

 dered to the first thoracic segment; and the latter is oblong and of difie- 



