CYCLOPOIDEA. 1207 



ovaries in some cases appeared to form a single oblong mass in the 

 cephalothorax. They were not convoluted or reticulate, as in the 

 Sapphirinae. The two oblong cavities within the abdomen connect 

 distinctly with the ovaries (see ^g. 5 Z>, PL 85). 



The distinction of the sexes was not ascertained. The test so appa- 

 rent in the Sapphirinae is not applicable here. I have looked for a 

 difference in the posterior antennae, but have made out none. There 

 are females with long fingers to these antennae, and others with very 

 short claws ; there are females with naked setae, and others with 

 the setae of these organs setulose ; and whether there be a distinction 

 in these organs, is a point yet undetermined. As with the Calani, 

 whose external sexual distinctions were not made out, numberless 

 specimens have been seen by the author. 



The stomach is a large sac, occupying in some species the greater 

 part of the cephalothorax. The oesophagus, where distinctly seen (fig. 

 5 a, PL 85), was elongate, and extended from the mouth to the lower 

 side of the stomach, instead of its anterior extremity. 



Some information with regard to the arrangement of the muscles 

 will be gathered from figure 5 a, Plate 85. 



The nervous system was particularly studied in a species of Sapphi- 

 rina, and will be described in our remarks on that genus. 



Corycoeus, Dana, Proc. Acad. Nat. Sci. Philad., ii. 285, 1845; Amer. J. Sci. [2], i. 

 218, viii. 280, ix. 133 ; Proc. Ainer. Acad. Sci., ii. 35, 1849. 



1. Antennae tostic-sj macrodactyl^:, digito non breviore quam carpus. 



A. SetOB caudales stylis valde breviores. [Cephalothorax postice (ad segmentum tertlurn) 



acutus, segmento quarto minore^] 



CORYCJEUS GRACILIS. 



Cephalothorax gracilis, ventre non carinato. Conspicilla fere contigua. 

 Antennce anticce breviter setulosce. Antennarum posticarum articulus 

 2dus digito brevior, setd longd, setulosd. Abdomen uni-articulatum, 

 ajnce subcylindrico fere triplo longius, basi angustum. Styli caudales 

 abdomine breviores, setis brevis&imis. 





