nesjEA. 247 



Coast of Devon. This and the following species swim 

 with great swiftness and elegance, and can execute rapid 

 and varied evolutions. 



Cymodocea rubra, Leach. — Of a red colour ; body some- 

 what linear, fissure of last joint equal in breadth through- 

 out, sixth segment without prolongation. 



Coast of Devon. Cumbrae, Firth of Clyde (Rev. Alfred 

 Norman) . 



Cymodocea viridis, Leach. — Of a green colour; body 

 nearly oval ; fissure of last segment of abdomen very wide 

 at the base. 



Coast of Devon. 



Gen. 126. NES^A, Leach. 



Last segment of the tail (last false legs) on each side with 

 a straight, slightly compressed appendage. Body six- 

 jointed; last joint larger than the rest. Antennas seta- 

 ceous, nearly equal, upper with a very large peduncle, two- 

 jointed, basal joint the larger. 



Nes^ea bidentata, Adams. Adams's Sea Pill-hall. 

 (Plate XIV. fig. 1.) — Body smooth, sixth ring terminated 

 behind by two sharp points; abdomen with its last ring 



