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Stat. 12S (700 metres to surface), 1 male. — Stat. 141 (1500 metres to surface), 1 female. — ■ 

 Stat. 276 (750 metres to surface), 1 male. 



My father has obtained specimens of a male form from the plankton collected in the 

 Faröe Channel, by the Scottish International Fisheries Cruiser 'Goldseeker', that is identical 

 with the male of the present species. 



The two species now described as new, may eventually prove to be the same as some 

 of. the new Attgaptilns, described by Professor G. O. Sars, in 'Bulletin du Musée Océanographique 

 de Monaco', part 2, (N° 40) 1905. Only the preliminary descriptions are there given. It is 

 very difïïcult to identify the members of this genus without illustrations. 



Genus Haloptilus Giesbrecht, 1898. 



The members of this genus are readily recognised by their transparent and flattened 

 body. The abdomen is comparatively short. It is composed of four segments in the female. 

 The endopodite of the antennae is much longer than the exopodite. 



Four species belonging to this genus were present in the plankton collected by the 'Siboga'. 



1. Haloptilus longicornis (Claus). 



Hemicalanus longicornis Claus, 1863, p. 179, pi. XXIX. 



Hemicalanus longicornis Brady, 1883, p. 44, pi. IX, figs. 1 & 7. 



Hemicalanus longicornis Giesbrecht, 1893, p. 384, pis. 1, 2, 27. 



Hemicalanus longicornis T. Scott, 1893, p. 32. 



Haloptilus longicornis Giesbrecht & Schmeil, 1898, p. 118. 



Haloptilus longicornis Sars, 1902, p. 121, pis. LXXXII & LXXXIII. 



Haloptilus longicornis I. C. Thompson, 1903, p. 28. 



Haloptilus longicornis Wolfenden, 1904, p. 135. 



Haloptilus longicornis Sars, 1905 (b), p. 4. 



Haloptilus longicornis Farran, 1905, p. 45. 



Haloptilus longicornis Pearson, 1906, p. 27. 



Haloptilus longicornis Farran, 1908, p. 67. 



Haloptilus longicornis van Breemen, 190S, p. 128, fig. 146. 



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

 at the followinor stations. 



ö 



Stat. 118 (Hensen vertical net, 900 metres to surface), 2 specimens. — Stat. 128 (Hensen 

 vertical net, 700 metres to surface), 2 specimens. — Stat. 129, 1 specimen. — Stat. 141 

 (HENSEN vertical net, 1500 metres to surface), 3 specimens. — Stat. 148 (Hensen vertical 

 net, 1000 metres to surface), 4 specimens. — Stat. 203 (HENSEN vertical net, 1500 metres 

 to surface), 4 specimens. — Stat. 220 (HENSEN vertical net, 200 metres to surface), 2 spe- 

 cimens. — Stat. 252, 1 specimen. — Stat. 276 (HENSEN vertical net, 750 metres to surface), 

 3 specimens. 



Haloptilus longicornis is a comparatively small form. It can readily be recognised by the 

 knob-like projection on the forehead when viewed from above, and by the very long antennules. 



This species has a wide distribution in the great oceans. It has been recorded from the 

 North Atlantic off the Coast of Norway, by Professor G. O. Sars. 



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