8 



A good part of the larvae can be determined, and among them are found specimens in the 

 Masiigopus-stages of .S. atlanticus M.-Edw., of which adult specimens were not taken, but as 

 these larvae can be determined with certainty, 5". atlanticus is dealt with below. — A single 

 specimen of a Mastigopus belongs to a hitherto unknown species of Group II, but it is omitted 

 as being somewhat mutilated and besides indeterminable. 



1. Serges tes atlanticus M.-Edw. 



1830. Ser gestes atlanticus H. Milne-Edwards, Ann. Sci. Natur. T. XIX, p. 346, PI. X. 

 1859. Ser gestes Frisii Kröyer, Kgl. Danske Vid. Selsk. Skrifter, 5. Raekke, Naturv.-math. 



Afd. IV, 2, p. 235, Tab. I, Fig. \,a — v. 

 1888. Ser gestes atlanticus Bate, Challenger Rep. Vol. XXIV, p. 389, Pis. LXVIII & LXIX 



(at least partially). 

 1896. Sergestes atlanticus H. J. Hansen, Proc. Zool. Soc. London for Dec. 1, 1896, p. 951. 

 1903. Sergestes atlanticus H. J. Hansen, Proc. Zool. Soc. London for 1903, p. 58. 



The Mastigopus. 



1859. Sergestes ancylops Kröyer, 1. c. p. 262, Tab. III, Fig. 8, a — e. 

 1888. Sergestes ancylops Bate, 1. c. p. 413, PI. LXXV, fig. 2. 

 1888. Sergestes ovatoculus Bate, 1. c. p. 408, PI. LXXIV, fig. 2. 

 1896. "-Sergestes ancylops" H. J. Hansen, 1. c. p. 952. 



Stat. 203. Sept 19. Lat. 3°32'.5S., long. i24°is'.5E. Hensen vertical net, from 1500 m. 



I Mastigopus. 

 Stat. 225. Nov. 8. 5700 m. N. 279 E. from Southpoint of South-Lucipara-island. Horizontal 



cylinder. 1 Mastigopus. 

 Stat. 276. Jan. 9. Lat. 6°47'.5 S., long. I28°40'.5 E. HENSEN vertical net, from a depth of 



750 m. 1 Mastigopus. 



The curious shape of the eyes, seen from above, renders the Mastigopus of S. atlan- 

 ticus easy to distinguish from all other forms hitherto known. In 1896 I pointed out that S. 

 ancylops Kr. and S. ovatoculus Bate are animals in Alastigopus-stages of 5. atlanticus, and in 

 1903 I gave a critical revision of the animals referred by Bate to S. atlanticus. 



The Copenhagen Museum possesses an extremely large collection of adult and subadult 

 specimens of 5. atlanticus, all gathered near the surface or at most in some few fathoms below 

 it, and generally during the nights. S. atlauiic?ts belongs to the open ocean, and it is one of 

 the few species of Sergestes, which during all stages live near or not very far from the surface. 



2. Sergestes inous Faxon. PI. I, figs. \a — \c. 



1893. Sergestes inous Faxon, Buil. Mus. Comp. Zool. Vol. XXIV, p. 216. 

 1895. Sergestes inous Faxon, Memoirs Mus. Comp. Zool. Vol. XVIII, p. 208, PI. LI, figs. 2 — id. 

 1901. Sergestes sp. ? inous Alcock, Descr. Catal. Indian Deep-Sea Crust. Dec. Macrura and 

 Anomola, p. 50. 



Stat. 35. March 28. Lat. 8°o'.3 S., long. u6°59'E. 1310 m. Deep sea trawl. 1 large male. 

 Stat. 175. August 30. Lat. 2°37'.7S., long. I30°33'.4E. 191401. Deep sea trawl. 1 immature 



male. 

 Stat. 208. Sept. 22. Lat. 5 39' S., long. I22°I2'E. 1886 m. Deep sea trawl. 1 immature 



specimen. 



