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slightly inflated genital segment of the female, by the short anal segment, and by the long 

 slender furcal joints. The furcal joints are about four times the length of the anal segment. 



This species appears to be rather sparsely distributed. It has been recorded from the 

 Indian and Pacific Oceans. 



1. Corycaeus carinatus Giesbrecht. 



Corycaeus carinatus Giesbrecht, 1891, p. 481. 

 Corycaeus carinatus Giesbrecht, 1S93, p. 661. pi. 51. 

 Corycaeus carinatus I. C. Thompson, 1900, p. 293. 

 Corycaeus carinatus Wheeler, 1900, p. 192, fig. 30. 

 Corycaeus carinatus A. Scott, 1902, p. 421. 

 Corycaeus carinatus Thompson & Scott, 1903, p. 285. 

 Corycaeus carinatus Wolfenden, (1905 (a), p. 1029. 

 Corycaeus carinatus Esterly, 1905, p- 226, fig. 62. 



One specimen identical with the above species was obtained fröm the plankton collected 

 with the Hensen vertical net at Station 203, 1500 metres to the surface. 



Corycaeus carinatus is closely related to Corycaeus rostrahts. The abdomen of the 

 female consists of a single segment, but it is distinctly more inflated than in Corycaeus rostrahts 

 and the furcal joints are moderately long, and slender. The length of the furcal joints is equal 

 to half the length of the abdomen. The furcal joints of Corycaeus rostrahts are equal to one- 

 fourth of the length of the abdomen. 



This Corycaeus has been recorded from the Atlantic, Indian, and Pacific Oceans. 



3. Corycaezts conciwnus Dana. 



Corycaeus concinnus Dana, 1847, pp. 150 — 154. 



Corycaeus concinnus Dana, 1852, p. 1225, pi. 86. 



Corycaeus concinnus Giesbrecht, 1893, p. 661, pi. 51. 



Corycaeus concinnus A. Scott, 1902, p. 421. 



Corycaeus concinnus Thompson & Scott, 1903, p. 286. 



Twenty-two specimens belonging to the above species were obtained from the plankton 

 collected at the following stations. 



Stat. 50, 3 specimens. — Stat. 141 (HENSEN vertical net, 1500 metres to surface), 10 spe- 

 cimens. ■ — Stat. 148 (Hensen vertical net, 1000 metres to surface), 4 specimens. — Stat 

 230 (HENSEN vertical net, 2000 metres to surface), 5 specimens. 



The female of Corycaeus concinnus can be recognised by the long and rather slender 

 abdomen. The abdomen consists of a single segment. The proximal end is distinctly inflated, 

 and the distal end is rather sharply contracted. The furcal joints are moderately slender and 

 are equal to about one-third of the length of the abdomen. 



Corycaeus concinmts has been recorded from the Indian and Pacific Oceans. 



4. Corycaeus danae Giesbrecht. 



Corycaeus danae Giesbrecht, 1891, p. 480. 

 Corycaeus danae Giesbrecht, 1893, p. 660, pi. 51. 



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