12 



OSCAR SUND 



(REP. OF THE "MICHAEL SARS" NORTH 



or appendages. On the outer uropods there are fine 

 dotted lines, just as in 5. splendens, which may also be 



luminous organs. 



As the name denotes, S. robustus is one of the 

 largest species in the genus. It should be mentioned 

 that the abdomen in 5. robustus is considerably longer 

 than in 5. mollis. The following table shows the number 

 of specimens of each size and sex: 



Length 

 (total) 





20 





30 





40 







50 





60 





70 







80 



Total 



L. of carap. 

 (mm) 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 



15 



16 



17 



18 



19 



20 



21 



22 



Males 



Females. . . . 

 Young 



10 



26 



1 

 44 



4 

 12 



4 



7 



12 



2 

 16 



2 



5 













1 

 1 



1 



1 





1 



1 



21 

 46 

 84 



(The figures given for total length are only approximate). 



(*fr) 



13 



Fig. 11—13. Sergestes robustus. 11) Petasma. after Smith (1884), (ca. 15 /i). 12) Tip of Petasma, <? 18,st. 53, 

 3 In 2600, ( 5 %). 13) Petasma, <? 8, st, 67, y 1200, ( 6 %). 



The peculiar feature of this table is that no specimens 

 between 11 and 17 mm C. were caught. Is this to be 

 interpreted as indicating that the material comprises two 

 (or three?) yearclasses? 



S. robustus was taken at 19 stations, on the northern 

 and southern sections, to the W. of the British Isles, and, 

 what is most remarkable, at st. 102 to the SE. of the 

 Faeroes, in the part of the Faroe-Shetland Channel be- 

 longing to the Norwegian Sea, as well as in the Spanish 

 Gulf and near the Canaries, but not on the route between 

 the Canaries and the Azores. 



It had previously been captured by ,, Blake" and 

 the "Albatross" off the New England coast (Smith), in 

 the Bay of Biscay by the "Caudan" (Caullery), in the 

 Mediterranean near Crete (Adensamer) and near Sicily 

 (Lo Bianco and Rigoio). It has been taken at a number 



of localities to the W. of Ireland, and by Danish and 

 Norwegian expeditions to the SW. of the Faroes. Gene- 

 rally it may be said that it is as yet known only from 

 the Gulf Stream and from Mediterranean watermasses, 

 inside and outside Gibraltar. Its apparent absence between 

 the Canaries and the Azores may be accidental. 



Vertical distribution of sizes. 



Depth 



Hauls 



Size (C in 



mm) 



Total 



(metres) 



5-8 



9—12 



17—22 





50—250 



10 



12 



12 





24 



251—500 



11 



33 



10 





43 



501—1000 



14 



36 



5 



1 



42 



> 1000 



8 



19 



14 



5 



38 



Total 



43 



,100 



41 



6 



147 



