ioo SHELVE DISTRICT 



s.s. except that the cardinal process always remains discrete from the brachiophores. 

 In other features, too, there is a noteworthy likeness between the two stocks which 

 differ only in the relative shortness of the dental plates and the fineness of ribbing 

 and poor development of secondary externals in sectors III and IV in the Shelve 

 samples. In the Whittery sample, 4, 5 and 6 costellae per mm were counted 5 mm 

 antero-medialry of the umbones of 3, 1 and 1 brachial valves ; while 3ala)3a°, 3c)3a° 

 and 4b)4b° occurred in 0/4, 1/5 and 1/2 brachial valves respectively. These 

 differences seem to be important enough to merit subspecific recognition. 



Table 64 



Statistics of length (1) and maximum width (w) of n brachial valves of Onniella ostentala lepida 

 subsp. nov. from the Aldress Shales (A) and Whittery Shales (B) 



A B 



n 11 22 



ljnm (var 1) 3-2 (0-638) 3-7 (1-149) 



w mm (var w) 4-12 (0-748) 4-99 (2-006) 



r 0-985 0-962 



log e l (var log e l) I-I 33 I (0-0604) 1-2694 (0-0804) 



logew (var logew) 1-394 (0-0429) 1-5679 (0-0775) 



r e 0-99 0-965 



a (var a) 0-843 (0-00158) 0-9815 (0-00329) 



Table 65 



Statistics of length (1) and depth (th) of 12 brachial valves of Onniella ostentata lepida subsp. nov. 



from the Whittery Shales 



1 mm (var 1) 4-22 (0-532) 



th mm (var th) 0-48 (0-012) 



r 0-865 



a (var a) 0-1527 (0-00058) 



Table 66 



Statistics of length (1) and depth (th) of 10 pedicle valves of Onniella ostentata lepida subsp. nov. 



from the Whittery Shales 



1 mm (var 1) 3-91 (0-761) 



th mm (var th) o-88 (0-068) 



r 0-493 



a (var a) 0-3 (0-00851) 



Table 67 



Statistics of length (1) of n pedicle valves and length of dental plates (dl) of Onniella ostentata 

 lepida subsp. nov. from the Aldress Shales (A) and Whittery Shales (B) 





A 





B 



n 



1 mm (var 1) 



dl mm (var dl) 



r 

 a (var a) 



9 



3-42 (1-017) 

 o-57 (0-034) 

 0-799 

 0-184 (o-ooi 



75) 



12 



3-91 (1-788) 

 o-6 (0-061) 

 0-909 

 0-185 (0-00059) 



