DISTRIBUTION AND GENERAL NOTES ON THE SPECIES 275 



Fie i8 to which frequent reference has been made in the notes on individual species, summarizes 

 the main 'features of their depth distribution. The statistical significance of the diiferences between 

 the effective mean depths observed for the several species, which are plotted m the figure, are given 



'"^ iT tm be seen that the species may be grouped into three classes according to their depth relations, 



'^l' Shallow, species of the shelf: Squalus lebruni, Raja flavirostris, R. magellanica, Psammobatis 



'''".^t^.: Raja maclo.i^a and R. brachyurops. The peculiar depth distribution of 

 the last named has been shown to be due to a seasonal migration over the shelf edge. The less common 

 R. macloviana shows a general depth relation of the same type (an hour-glass or dumbbell-shaped 

 polygon), and there are other grounds for supposing that a similar migration in tha species is po sible 

 m. Deep-water species found almost exclusively over the shelf edge: R. doello-juradot, with the 

 rarer forms R. scaphiops, R. alhomaculata and R. griseocauda. 



CLUPEIDAE 



Clupea fueoensis (Jenyns). This is one of the most numerous and important species of our area, but 

 ^C^l main y pela ic habits and small (' Pochard ') size, it could not be adequately sampled wi h 

 ol ge For this reason I give only the list of stations where it was captured. The numbers mean 

 3i tie. The Falkland herring is a most important forage fish for l-g-/P--;. ^^f^^^^.^tr' 

 anZi also extensively eaten by birds and seals. It is possible that it could be utilized directly for 

 human ood-it is most excellent eating, as the Falkland islanders well know-but prospects of 

 regTr a^- m numbers sufficient to support, say, a small canning factory are not good. Any 

 fofm of gm net would be continually threatened by seals and penguins anywhere wi hin reasonable 

 SllLce of the Falkland Islands, while the herring trawl would almost certainly fail on the rough 

 bottom Some specialized form of purse seining might possibly provide an answer. 



Some other clupeoids recorded from the Patagonian region may be mentioned here, though we d.d 

 not cTotu e any of them and they are probably not normal inhabitants of the area surveyed. The 

 ; c es rr^ownTchU "; ' sardina' was Lnd by Norman (:937, P- 38) to be quite di^mct from the 

 vTa ly ealrn C.fuegensis. Norman has named it C. berrtincki, after Mr Cavendish Bentinck, who 

 sIntHm a tne series Lm Talcahuano harbour. From Col. Tenison's drawings it can at once be 

 Te^n Z I is much deeper in profile than the species so common on the continental shelf to the east. 

 It resembles typical northern hemisphere herrings much more closely. 



Gunther has a note that Clupea sp. (? maderen.s) was on sale at the -/^^ ^ ^^^ t"; f Itfs 

 u f oAor^T^rnv This soecics he savs, s represented farther south by C. /z^c^ewm. n is 



smaller than C. fuegensis, of ' sprat ' as compared with ' pilchard size. ^ 



We obtained specimens of C.friegensts at the following stations, mostly in the accessory 



S wis WS^So A TS8%B WS^3S 



^fi4 ^St Ws4b WSS^S S^f/,(N:ooB) 



Also: Stanley Harbour, 2. .i. zj and Chartres River, West Falkland Islands, 13. iii- 33- 



