DAVENPORT. 



EVOLUTION OF PECTEN. 



159 



Ai^rENDICES I, K. 



Correlation Surface : Ears and Antero-posterior Diameter. 



Irish Sea. Length of Ears. 



Anterior, millimetres. 

 3/= 17.255 ± .040 ; <r = 1.375 + e .028. 



Posterior, millimetres. 

 M = 14.821 ± .040 ; o- = 1.378 ± .028. 



so 



il 



b 



-H 



25 1 



37; . 



38 . 

 40! . 



41 . 



42 . 



44 . 



45 . 



46 . 

 50 . 



52 . 



53 . 



54 . 



55 . 



56 . 



57 . 



58 . 



59 . 



60 . 



61 . 



62 . 



63 . 



64 . 



65 . 



66 . 



67 . 



68 . 



69 . 



70 . 



71 . 



72 . 



73 . 



74 . 



75 . 



76 . 



77 . 



78 . 



79 , 



80 . 



10 11 12 13 



1415 



16 



4 12 26 



17 



18 19 20 21 



155181 47 21 2 



= 541 



/ 9 10 11 12 13 14 15 16 17 18 19 20 



19il4 

 8 21 



8 42 139 162.138 30 4 



2 



2 



4 



3 



1 



5 



6 



8 



13 



12 



19 



28 



26 



34 



32 



27 



58 



43 



33 



36 



33 



32 



16 



17 



16 



10 



8 



3 



1 



:54i 



