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of 1 10 mm. That Coi.i.irr r's specimen was far forward in development is seen from the 

 measurements given (distance from the tip of the snout to the anal fin was = 48 mm. 

 and height of body = 7 mm.), and further in that it had no teeth. 



These takes of the conger Leptocephalus — or metamorphosis stages — outside the 

 Atlantic so far to the east are of considerable interest, especially in comparison with the 

 common eel. There can be no doubt that the conger like the latter reproduces and 

 develops to the larval stages (Leptocephali) in the Atlantic west of Great Britain and 

 France; this is shown both by the earlier investigations and the later with the "Thor". 

 There is this difference between Conger and Anginlla, namely, that some specimens ot 

 the Leptocephalus stages (1st— 4th inclusive) of the former have been found to the east 

 of Great Britain', whilst not a single specimen of the latter younger than at the beginning 

 of the 5th stage has been found so far east. What the reason for this is cannot be 

 determined from the present state of our knowledge. The explanation may perhaps be 

 that the metamorphosis and therewith the pelagic life near the surface is of longer 

 duration in the conger than in the eel^, with the result that the Leptocephali of the 

 former are more exposed to be carried far by the currents and also to be driven in to 

 shallow water close to the coasts. This may also be indicated by the fact, that relatively . 

 so many of the conger Leptocephali taken near the coast were in process of metamor- 

 phosis or far forward in development, as also by the fact, that the conger Leptocephali are 

 comparatively so frequently found stranded on the coast in the Mediterranean (Sicily). 



If this view is right, that the pelagic life and metamorphosis of the conger larvae 

 are of longer duration than the eel's, it seems to me also not so difficult to understand 

 why some of the conger still in the Leptocephalus stage can be driven from the Atlantic 

 eastwards into the North Sea in autumn and winter, just as we know that the young of 

 the eel (which at this time of year have already passed through the Leptocephalus stage) 

 are in winter carried into the North Sea both south and north of Great Britain. 



It is also perhaps possible however that the conger eels reproduce and develop nearer 

 to the coasts than the common eels, which would also help to explain the (occasional?) 

 appearance of its Leptocephalus stages near the coasts, but as we still know too little 

 positively about the subject, it is of no use to go further into the matter for the moment. 



2. Leptocephalus Synaphobranchi -pinnatii (Pi. IX, Fig. 4— 6) 

 39 specimens of this form were taken, 38 in June and 1 on Sept. 1st, 1905. In all 

 the June specimens the anus was placed far back, only in the Sept. specimen had it 

 begun to move forwards, which means that the metamorphosis had begun (Fig. 6, PI. IX). 



1 It should be remarked however that by far the greater number of the specimens of the conger Lep- 

 tocephalus known from North and West Europe have been taken in the Atlantic to the west of Great Britain 

 and France. 



2 The Scottish and Norwegian discoveries mentioned seem also to show that the metamorphosis of the 

 conger often takes place in midwinter, therefore later in the year than that of Anguilla, in spite of the fact 

 that Leptocephahis Morrisii (i. e. the larva of the conger in the ist stage) was found by the "Thor" to occur 

 in June 1905 along with Leptocephalus breviroslris in the ist stage in the Atlantic to the west of the 

 British Isles. 



3 At my request this Leptocephalus was examined by Cand. Mag. Ad. JENSEN' who (from the number of 

 vertebrae etc.) has identified it with Synaphobranchns pinnatus, one of the commonest deepwater eels of the 

 northern Atlantic. 



