CYCLOPOIDEA. 1Q55 



Calanus furcicaudus. 



From triangidatus. Cephalothorax 4=-artieidatus, capite subito angus- 

 tatus, postice obtusus* Antennae anticce corpore pernio breviores, duplo 

 curvatce, apicibus f route posterioribus, ferrnh 24 (2Q7)-articulatce; arti- 

 culo ultimo paulo longiore ; setis brevibus, prope basin numerosis, 

 apicalibus articulo paulo longioribus et anticis apice parch remotis, 

 subapicalibus minutis. Styli caudales setosque lath divaiicati, setis 

 incEquis, secwiclis abdomine longioribus. 



Front triangular. Cephalothorax rather stout, four-jointed, head 

 abruptly narrower, obtuse behind. Anterior antennae a little 

 shorter than the body, doubly curved, apex behind line of beak, 

 twenty-four (twenty-six?) -jointed; last joint (perhaps a double 

 one) somewhat longer than either of the three preceding; setae near 

 base numerous and short (twice longer than diameter of joints), 

 the anterior and posterior apical elongate (nearly as long as last 

 two joints), the anterior remote from apex, subapical setae minute. 

 Caudal stylets and setae widely divergent, setae unequal, the second 

 longer than the abdomen. 



Plate 72, fig. 6 a, animal, enlarged ; b, extremity of anterior an- 

 tennae ; c, profile of abdomen. 



Collected in the Pacific, a few miles southeast of Pitt's Island, the 

 northern of the Kingsmills, latitude 3° north, longitude 173° east, 

 April 28, 1841. 



Length, one-twelfth of an inch. Nearly colourless. The subacute 

 triangular front of this species and furcate caudal extremity, the setae 

 and stylets diverging with a curve, are striking characters of this 

 species. In addition, at the apex of the anterior antennae the poste- 

 rior and anterior setae are somewhat long and nearly in the same line, 

 while the setae of the preceding joints are quite short. At the apex, 

 in addition to the longer anterior setae a short distance back from the 

 apex, there are two quite short anterior just at the apex. The ante- 

 rior seta of penult joint is about as long as diameter of joint ; the 



