>4' 



2. Haloptilus ornatus (Giesbrecht). 



Hemicalanus ornatus Giesbrecht, 1S93, p. 384, pis. 27 & 42. 

 Haloptilus ornatus Giesbrecht & Schmeil, 1898, p. 120. 

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

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

 Haloptilus ornatus van Breemen, 1908, p. 130, fig. 14N. 



One specimen of this Haloptilus was found in the plankton collected with the Hénsen 

 vertical net at each of the followingf stations. 



Stat. 118 (900 metres to surface). — Stat. 128 (700 metres to surface). 



This species can easily be separated from the other members of the genus by its narrowly 

 rounded forehead, and by the strong curved spines on the apical lobes of the first pair of 

 maxillipedes. The antennules extend beyond the end of the furca by about four joints. 



Haloptilus ornatus was originally described by Giesbrecht from Mediterranean specimens. 

 Thompson, Sars and van Breemen have since recorded it from other areas. 



3. Haloptilus plumosus (Claus). 



Hemicalanus plumosus Claus, 1863, p. 178, pis. XXVIII & XXIX. 

 Hemicalanus plumosus Giesbrecht, 1893, p. 384. 

 Hemicalanus plumosus T. Scott, 1893, p. 33, pis. II & VI. 

 Haloptilus plumosus Giesbrecht & Schmeil, 1898, p. 119. 



One specimen belonging to this species was found in the plankton collected with the 

 Hensen vertical net at Station 141, 1500 metres to the surface. 



Haloptilus plumosus resembles Haloptilus ornatus in general appearance. It can be 

 distinguished by its shorter antennules, and by the endopodite of the maxillae being furnished 

 with four setae. 



This species has hitherto only been known from the Mediterranean and from the Gulf 

 of Guinea. 



4. Haloptilus spiniccps (Giesbrecht). 



Hemicalanus spiniceps Giesbrecht, 1893, p. 384, pis. 27 & 42. 

 Haloptilus spiniceps Giesbrecht & Schmeil, 1898, p. 120. 

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

 Haloptilus spiniceps Sars, 1907 (a), p. 19. 

 Haloptilus spiniceps van Breemen, 1908, p. 130, fig. 149. 



One specimen of this Haloptilus was obtained from the plankton collected at each of 

 the following stations. 



Stat. 128 (HENSEN vertical net, 700 metres to surface). — Stat. 185 (HENSEN vertical net, 

 1536 metres to surface). — Stat. 203 HEXSEX vertical net, 1500 metres to surface). — 

 Stat. 220 (HENSEN vertical net, 200 metres to surface). — Stat. 315. 



This species can readily be separated from the other members of the genus by the short, 



141 



