DISCUSSION OF SPECIES 



i»i 



the species was made valid a year later with descriptions and 

 figures of both sexes. 



Corycaeus flaccus Giesbrecht 



(Figure 50) 



[Corycaeus flaccus Giesbrecht, Atti R. Accad. Liiicei, Rome, ser. 

 4, vol. 7, sem. I, p. 480, 1891; Fauna und Flora des Golfes 

 von Neapel, vol. 19, pp. 659-674, pi. 51, figs. 10, 11, 1892.] 



Found at the first three localities in the Atlantic, in the 

 Caribbean, and in every region of the Pacific, except above 

 40° north latitude, but with numerous and extensive gaps. It 

 was present in 4 nocturnal surface tows, and in the daytime 

 was taken in 10 surface tows, 22 50-meter tows, and 18 100- 

 meter tows, and in the vertical tow from 1000 meters at 

 station 64. It may be recognized in side view by the small 

 knob projecting from the distal end of the dorsal surface of 

 the genital segment. 



Corycaeus furcifer Claus 



[Corycaeus furcifer Claus, Die freilebenden Copepoden, p. 157, 

 pi. 24, 1863.] 



Found at station 32 in the Caribbean, and, like the pre- 

 ceding species, scattered in every region of the Pacific with 

 numerous and extensive gaps in distribution, but not above 

 40° north latitude. It was taken in i nocturnal surface tow, 

 and in the daytime was present in 3 surface tows, 6 50-meter 

 tows, and 8 loo-meter tows. In side view the posterior end of 

 the genital segment carries a dorsal pointed spine. 



Corycaeus giesbrechti F. Dahl 



(Figure 37) 



[Corycaeus giesbrechti F. Dahl, Verhandl. Deut. zool. Ge- 

 sellsch., vol. 4, Miinchen, p. 72, 1894Z'.] 



Not found in the Atlantic plankton, but present in the 

 southeastern and central regions of the Pacific and even more 

 widely scattered than the two preceding species. It was taken 

 once at the surface in the night, and in the daytime was 

 found in 3 surface tows, 3 50-meter tows, and 2 loo-meter 

 tows. The genital and anal segments are slender and each is 

 twice as long as wide; the caudal rami are of the same length 

 as the anal segment. 



Corycaeus lautus Dana 



[Corycaeus lautus Dana, Proc. Amer. Acad. Arts and Sci., \'ol. 

 2, p. 37, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), 

 vol. 14, pt. 2, Crustacea, p. 1219, 1853; pi. 85, fig. 12, 1855.] 



Found at the first Adantic station, at six stations in the 

 Sargasso and Caribbean regions, and in every region of the 

 Pacific except the far north. It was present in 5 nocturnal 

 surface tows, and in the daytime was taken in ig surface 

 tows, 22 50-meter tows, and 22 loo-meter tows; al.so taken in 

 the vertical tow from 1000 meters at station 64. This is the 

 longest of all the species of the genus, and the genital seg- 

 ment is but litde wider than the anal segment. 



Corycaeus limbatus Brady 



[Corycaeus limbatus Brady, Voyage of H.M.S. Challenger, 

 Zool., vol. 8, pt. 23. Copepoda, p. 1 14. pi. 49, 1883.] 



Found at four localities in the Atlantic and fairly abundant 

 in the southeastern Pacific, but very scattering elsewhere. It 

 was taken in 5 nocturnal surface tows, and in the daytime in 

 19 surface tows, 19 50-meter tows, and 20 loo-meter tows, an 

 exceptionally uniform vertical distribution. The urosome is 

 one-segmented in the female, slender and tapered evenly both 

 anteriorly and posteriorly; the terminal claw of the second 

 antenna is exceptionally short. In the male the urosome is 

 two-segmented, the genital segment much wider than the 

 anal segment, the latter abruptly narrowed; the terminal claw 

 of the second antenna is much longer. 



Corycaeus longistylis Dana 



[Corycaeus longistylis Dana, Proc. Amer. Acad. Arts and Sci., 

 vol. 2, p. 36, 1849; U. S. Exploring Exped., 1838-1842 

 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1212, 1853; pi. 85, fig. 

 5a-d. 1S55.] 



Not found in the Atlantic plankton, but common in the 

 southeastern and central regions of the Pacific. It was cap- 

 tured in 2 nocturnal and 25 diurnal surface tows, 33 50-meter 

 tows, and 30 100-meter tows; also in the vertical tow from 

 1000 meters at station 64. The urosome of the female is two- 

 segmented, the genital segment nearly twice as wide as the 

 anal segment, the latter abruptly narrowed. The posterior 

 processes of the third thoracic segment reach backward be- 

 yond the posterior margin of the genital segment. 



Corycaeus lubbockii Giesbrecht 

 (Figure 38) 



[Corycaeus lubboc\ii Giesbrecht, Atti R. Accad. Lincei, Rome, 

 ser. 4, vol. 7, sem. i, p. 481, 1891; Fauna und Flora des 

 Golfes von Neapel, vol. 19, pp. 660, 674; pi. 51, figs. 51, 57, 

 58, 1892.] 



Not found in the Atlantic plankton, but present at four 

 stations in the eastern, central, and western parts of the 

 tropical Pacific. It was taken twice in the surface tow, once in 

 the 50-meter tow, and once in the loo-meter tow. In the 

 female there is a small knob on the dorsal surface of the 

 genital segment, and in both sexes the anterior margin of the 

 genital segment carries a small medium spine on the ventral 

 surface. 



Corycaeus minimus F. Dahl 



(Figure 39) 



[Corycaeus minimus F. Dahl, Verhandl. Deut. zool. Gesellsch., 

 vol. 4, Miinchen, p. 71, i894/;'.l 



Found at three stations in the Atlantic and two in the 

 southeastern Pacific. It was present three times in the surface 

 tow, once in the 50-meter tow, and twice in the 100-meter 

 tow. This species is very small, the anal segment is nearly as 

 wide as long, and the caudal rami are twice as long as the 

 anal segment. 



