120 BoHji Plates of John Donj 



So far as can be judgcil from such a sni.ill iiuiiil)ir of specimens thc foUowing 

 points seem worth iidtiiig: — 



1. The plates are arraiigeil syiniiietrically in mily li.Sö per eent. of the 

 whole. 



2. The average niimber of plates is 340, am! thc actuiil uuinbers of iiiost 

 frcqueiit ocourrence 34, 3."), and 36 (oiie of these three oucunlng in over 60 per 

 Cent, of the total). 



8 I 8 



3. The most frequent combination is ^^-t-^ which occurs in 10 per cent. of 



J I .) 



the total; the other most iisnal conibinations aro those in wliieti one or both of 

 the uppcr series are increased to 9. 



i Ti 1 f K f I f . ] in 10 I 11 , 9 I 11 , 



4. Ihe largest iiuniber oi plates iioted was 40, - ~ and ^, aiul 



7 I 7 

 the smallest 29, ^ „ . 



7 ö 



