48 BEITISH COPEPODA. 



The maxilla (fig. 3) is bisetose ; the anterior £oot-jaw 

 (fig. 4) has a broad basal and an attenuated apical 

 joint, which bears four stout terminal setas, and at the 

 base one long ciliated spine and two shorter spines. 

 The last joint of the posterior foot-jaw is in both sexes 

 short and broadly ovate, in the female bearing four 

 stout spines (fig. 5), in the male (fig. 6) a fringe of mar- 

 ginal setaB and a long curved terminal claw. The 

 inner branch of the fourth foot (fig. 7) is 1-jointed, 

 stout, nearly as long as the entire outer branch, and 

 has a truncate extremity, from which spring two long 

 and stout spines, and which is produced into a sharp 

 tooth at the internal angles ; the margins densely and 

 finely ciliated. Fifth pair of feet uncinate, bisetose. 

 The abdomen of the female (fig. 8) is very slender, the 

 first joint considerably longer than the following three, 

 third joint very small, only about half as long as broad, 

 second joint twice as long as the third, fourth nearly 

 twice as long as the second. The tail-segments are 

 excessively long and narrow, equal in length to the 

 first abdominal somite, and about ten times as long as 

 broad ; the external margin bears one small seta near 

 its middle, and the apex four or five slender setse, one 

 of which is nearly as long as the entire abdomen 

 (tail -segments included), another about half as long, 

 the rest being quite small. The first abdominal 

 segment of the male (fig. 9) is as broad as long, trun- 

 cate behind, its posterior angles each bearing a stout 

 spine and two or three short setse ; the remaining four 

 segments are from side to side only about one third 

 the bulk of the first, otherwise they and the caudal 



