588 LÖNNBERG, OBSERVATIONS ON CERTAIN FLAT-FISHES. 



The annual »rowth would then be about 3 — 4 cm. in this 

 species also. Of course I do not venture to assert that the 

 above-given result of my measureinents is perfectly correct, but 

 it seenis at least verv probable and I do not understand why 

 the sizes of the fishes should be so regularly grouped, if it does 

 not depend upon equal diflference in age. At the same time it 

 must be observed that all raeasurements given are of fishes 

 caught, at about the same time and nearly in the same place, 

 off Anholt, and that the statements only concern them. 



The largest brill I saw there measured 69 cm., the largest 

 plaice 70 cm. and the largest sole 47 cm. 



Table 2. 



Hybrid (plaice and flounder). 



Length of body expressed in inilliinetres 



Length of head (percentage of the total length) 



Greatest depth of body > > > '^ '" 



Least > » » » » » » » 



Postorbital length of head » » » » » 



Distance between anal fin and tip of snout * j » » » 



Length of pectoral fin of the eye side > » » !> » 



3> » 5. » » 5> blind 5> » » » » 2> 



» » ventral i » » eye » » > > » 



» 3> middle rays of caudal tin . . » > » » » 



Nmnber of rays in the dorsal fin 



s * y - 1 anal > 



495 

 23,2 

 39,3 



8,0 

 15,5 

 33,9 

 11,3 



9,6 



7,8 



18,3 



74 



49 



Table 3. 



Aberrant variety of the plaice. 



Total length of body expressed in millimetres 



Length of head (percent. of the total length) 



Greatest depth of body » »>^ » 



Least > »» » »>s s 



Postorbital length of head > » » » » 



Lengthof branch of lowerjawon the blind side » » » » » 



Distance between the anal fin and tip of snout » s » » » 



Length of the pectoral fin of the eye side » > » j> » 



» » » ventral »x»»» » >»» » 



» > » middle rays of the caudal » » > » j 



Number of rays in the dorsal fin 



> > > > » anal > 



335 

 20,2 

 38,8 



7,8 



14,0 



7,4 



28,9 



8,6 



8,0 



18,1 



74 



56 



