CYCLOPOIDEA. ^067 



Calanus pellucidus. 



Frons rotwidatus. Cephalothorax 5-articulatus, postich ohtusus, articulo 

 ultimo hrevi. Antennas anticce corporis longitudine, setis subapicalibus 

 posticis longiuscidis. Styli caudales oblongi. 



Front rounded. Cephalothorax five-jointed, behind obtuse, last seg- 

 ment short. Anterior antennae about as long as the body, posterior 

 subapical setae rather long. Caudal stylets somewhat oblong. 



Plate 73, fig. 7, animal, enlarged, the antennae not quite accurate in 

 the articulations or setae. 



Taken in the Atlantic, October 5, 1838, latitude 14 i° north, longi- 

 tude 21° west. 



Length, one twenty-fourth of an inch. Colourless. Length of cepha- 

 lothorax about four times its greatest breadth, some appearance of 

 an articulation is distinguished within, near middle of cephalothorax. 

 Beak bears below two spines, extending downward, which are rather 

 long. The eyes small; pigment deep reddish black, and nearly quadri- 

 lateral in form, rather larger than usual. Abdomen three-jointed ; 

 setae of moderate length. 



The stomach is a long oval sac ; and the intestine beyond, which 

 commences at the first articulation, is half its diameter. The heart 

 gave two hundred and fifteen palpitations in a minute. 



Calanus affinis. 



From rotundatus. Cephalothorax b-articulatus, postice obtusus, articulis 

 4 posticis subcequis. Antenna? antico3 corporis longitudine, apicibus 

 fronte posterioribus ; setis brevibus, duabus posticis subapicalibus prm- 

 longiSy anticd penultimd dimidio breviore, apicalibus brevibus. /Styli 

 caudales perbreves, setis diffusis, secundis fere duplo longioribus quam 

 prima?. 



Front rounded. Cephalothorax five-jointed, obtuse behind, four 

 posterior segments about equal in length. Anterior antennae as long 



