11(5 



Bonji Plates of John Dory 



9 19 

 or . This syniraetry only occurs in 23 6 per cent. of tlie total mimber 



8 I ö 



examined. 



The arrangement of the plates. 



Tlie most convenient way of dcaling with the various combinations of numbers 

 of plates foiind in these specimens seems to be by reference to their symmetry in 

 one or both series. 



Among the 250 specimens : — 



1. Both series of plates are sj'inmetrical in 59 or 236°/„. 



2. One series is asymmetrical in 112 or 44-8°/^. 



3. Both series are asymmetrical in 7!) or 3l"lj %. 



1. Among the symmetrical specimens the following arrangements occur: — 



["w I «1 

 \_m I 7nJ ■ 



2. Among the 112 asymmetrical in one series the following arrangements 

 occur : — 



(a) or the formula '^ "*" ^ \ " , 33 or 13-2 7„. 



(b) Of the formula " | " "^ ^ , 32 . .r 12s''. 

 »7t m 



(c) Of the formula " , " , 26 or U)-4 7„ 



