1052 CRUSTACEA. 



Calanus nudus. 



Frons rotundatus, prominulus. Cephalothorax A-articulatus, postice 

 subacutus. Antennce anticce cephalothorace vix longiores, ferme 18-ar- 

 ticulatce, articulo ultimo non longiore, apicibus fronte paulo anteriori- 

 bus; selis totis brevissiniis, apicalibus articulo non longioribus, et anticis 

 ab apice vix remotis, subapicalibus minutis. Styli caudales paulwm 

 oblongi, setis rectis, strictis, abdomine nan longioribus. 



Front rounded, little prominent. Cephalothorax long elliptical, four- 

 jointed, a little prominent in front and obtuse, subacute behind. 

 Anterior antennee shorter than the body, doubly curved, apices in 

 advance of the line of beak, appearing naked, setaa all very short 

 (shorter than breadth of joints), apical not longer than last joint, 

 subapical minute. Caudal stylets somewhat oblong ; setae straight, 

 parallel, not longer than abdomen. 



Plate 72, fig. 3 a, animal, enlarged ; b, second pair of antennae. 



Taken in great numbers, October 20, 22, 25, November 1, 3, 5, 8, 12, 

 1838, in the Atlantic, latitude 8° north to equator, longitude 21° to 

 18° west, and from the equator to 6° south, longitude 18° to 25° west. 



Length, one-twentieth of an inch. Colourless, or a little red about 

 the articulations. On account of the very short setae of the antennae, 

 its even outline without very prominent articulations, the slender 

 abdomen, and straight, not spreading caudal setae, the individuals 

 have a naked look. The last three joints of the cephalothorax are 

 about one-third its whole length. The beak is short. In a vertical 

 view the front margin between the antennae is prominent, but obtuse. 

 The abdomen is apparently three-jointed, yet the first articulation is 

 somewhat uncertain. The antennae when in position, have the apices 

 a little in advance of the line of the beak, and in this respect, as well 

 as others, the species differs from the preceding. 



Other specimens were obtained in the Atlantic on October 13 and 

 15, in latitude 8°-9° 20' north, longitude 23° 40'-24° 15' west, which 

 are believed to be identical with the G. nudus. Length, one-twenty- 

 fourth of an inch. Colour, rose-red, a little purplish and deepest 



