CYCLOPOIDEA. 1073 



clavatis et dliis setis brevibus uncinatis instructo, setis apicalibus et 

 anticis subapicalibus perbrevibus, subapicalibus posticis articulo vix 

 longioribus, incequis. Styli caudales breves, setis pared diffusis aut 

 appressis. 



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

 ment very short. Anterior antennae nearly straight, a little 

 shorter than the body, the first or basal joint elongate (probably 

 double), furnished with three pendulous subclavate setae, and others 

 quite short, apical and anterior subapical setae very short, posterior 

 subapical setae slightly longer than joint. Caudal stylets short, 

 setae not spreading. 



Plate 74, ^. 3a, animal, enlarged; b, bases of the same, more 

 enlarged ; c, extremity of antenna. 



Collected, October 22, 1838, in the Atlantic, latitude 6° north, lon- 

 gitude 21° west. 



This specimen had three or four setae pendant from the anterior 

 margin of the basal joint of the antennae (fig. 3 b), which were co- 

 loured reddish orange, like the central portions of the cephalothorax. 

 They were nearly as long as whole base. Besides these, there were 

 on the base a few uncinate setae. Cephalothorax a little broader pos- 

 teriorly, and somewhat truncate behind. The abdomen linear; the 

 stylets about as long as last joint of abdomen. The caudal setae were 

 mostly broken off. Apical joint of longer branch of posterior antennae, 

 about one-third the length of the branch ; the other branch much the 

 shortest. Four pairs of natatories. Abdomen five-jointed. 



2. Cephalothorax postice acutus, angulis posticis abdominem appressis. 

 Calanus SIMPLICICAUDUS. 



Frons obtusus. Cephalothorax 5-articidatus, segraento postico angusto et 

 postice bremssimh acuto. Antennce anticce corpore paulo longicves, bad 

 arcuatos, alioque fere rectce, apicibus f route pared posterioribus ; setis 

 brevibus, duabus subapicalibus posticis longis, inwquis, anticd penul- 



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