DISTRIBUTION AND GENERAL NOTES ON THE SPECIES 



331 



mechanism it is difficult to see how the species is maintained within its ecological norm, for the contra- 

 natant abilities of the young fish cannot be great during their second year of life (cp. E. S. Russell, 



1937. P- 321)- 



WS71 



WS72 



WS73 



WS76 



WS77 



WS78 



IVS79 



WS80 



WS81 



WS83 



WS84 



WS85 



WS86 



WS87 



WSgo 



WSgi 



WS92 



WS93 



WS94 



WS95 



WS96 



WS97 



WS98 



WS99 



WS108 



WS109 



WS210 



WS211 



WS'ziz 



WS213 



WS214 



WS215 



WS'216 



WS'217 



125 



4 

 90 



42 



3 

 2 



125 



42 



74 



136 



I 



5 



lOIO 



I 



4 



72 

 191 



18 

 270 



92 



I 



1615 



43 



18 



166 



10 



27 



63( + ) 

 I 



7 



1362 



I 



117 

 358 



WS218 



WS219 



WS220 



WS222 



WS223 



WS225 



WS226 



WS234 



WS235 



WS237 



WS23g 



WS242 



WS243 



WS244 



WS245 



WS246 



WS248 



WS250 



WS756A 



WS756B 



WS764A 



WS764B 



WS765 



WS771 



WS772 



WS773 



WS774 



WS775 



WS776 



WS781 



WS784 



WS785A 



WS785B 



WS785C 



232 



8 



26 



19 

 I 



27 

 I 



22 

 4 



47 



24 

 I 



25 



30 



35 



31 



13 



I 



2 



14 



9 



41 



17 



221 



2 



8 



II 



I 



2 



29 



13 



6 



10 

 4 



WS787 



WS788 



WS789 



WS790A 



WS790B 



WS79iB 



WS792A 



WS792B 



WS793 



WS794 



WS795 



WS796A 



WS796B 



WS797B 



WS797C 



WS798 



WS799A 



WS799B 



WS800A 



WS800B 



WS801 



WS802A 



WS802B 



WS804A 



WS804B 



WS8o^ 



WS806 



WS807 



WS808 



WS809A 



WS809B 



WS810 



WS811II 



WS812II 



140 

 I 



2 



4 



3 



57 



432 



432(+; 



220 



85 

 70 



247 



22 



I 



7 



2 



48 



49 

 12 



42 

 I 



3 

 I 



16 



41 

 6 



104 



20 



36 

 64 



3 

 16 



14 



15 



WS813 



WS814 



WS815 



WS816 



WS817A 



WS817B 



WS819A 



WS823 



WS824 



WS82S 



WS837 



WS838 



WS839 



WS847B 



WS848 



WS849 



WS850 



WS851 



WS853 



WS855 



WS8s7 



WS858 



WS859A 



WS859B 



WS860 



WS862 



WS864 



WS866 



WS868 



WS870 



WS874 



22 

 I 



23 



14 



4 



7 

 I 

 I 

 2 

 4 

 3 

 7 

 5 

 5 



17 

 4 

 5 



18 

 82 



4 

 42 

 15 



7 

 35 



8 

 16 



We also captured N. ramsayi with 'Other gear' at the following stations: 



51 

 652 



WS750 

 WS752 

 WS754 



35 (in OTL) 

 2 (in OTL) 

 I (in NR) 

 I (in NR) 

 I (in NR) 



WS755 

 WS767 

 WS779 

 WS832 

 WS852 



5 (in NR) 

 10 (in NR) 



I (in NR) 



6 (in NR) 

 12 (in BTS) 



WS856 

 WS861 

 WS863 

 WS865 

 WS867 



3 (in BTS) 



I (in BTS) 



16 (in BTS) 



23 (in BTS) 



15 (in BTS) 



WS871 I (in BTS) 

 WS874 I (in NR) 



N. ramsayi was rarely abundant in depths of less than 100 m., and never observed by us in depths 

 of less than 50 m. The 'effective mean depth' was found to be 151 m., but the dispersion was very 

 wide as can be seen from the diagram in Fig. 42. It will also be noted that the depth-frequency 

 polygon tends towards the dumbbell shape, though the upper mode is by far the greater. In view of 

 our findings with Raja brachyurops it was therefore obviously desirable to test the possibilities of a 

 seasonal migration over the shelf edge in order to account for this. The data were arrayed by seasons 

 in 50 m. depth categories and relative abundance, as indicated by numbers of N. ramsayi per hour's 

 trawling, was computed for each. 



The resuhs shown in Table 31 are also indicated diagrammatically in Fig. 37. The graphs in the 

 top half of this figure seem sufficient to show that the very varied amount of trawling within individual 

 depth categories does not affect the main result ; namely that A^. ramsayi shows a well-marked migration 

 into deep water over the shelf edge in winter and is relatively most numerous on the shelf in summer 



Actual numbers of A^. ramsayi were highest in autumn, at all but the greatest depths. Nearly half 

 the rich hauls of more than 100 individuals and all three exceptional hauls of more than 1000 m- 



