34 SHELVE DISTRICT 



outcrops near the top of steep tributary to Crowsnest Dingle, 350 yds WNW from 

 Blakemoorflat (Grid Ref. SJ 373008). 



Discussion. Representatives of Palaeoglossa have been recovered from most 

 formations constituting the Ordovician successions of the Shelve area, but samples 

 giving some indication of the variability in the shape of the shell and the develop- 

 ment of internal features have been obtained from only the Mytton Flags and the 



Table 15 



Statistics of length (1) and maximum width (w) of n brachial valves of Palaeoglossa attenuata 



(J. de C. Sowerby) from Meadowtown Beds (A) and the Rorrington Beds (B) and of Palaeoglossa 



myttonensis sp. nov. from the Mytton Flags (C) 





A 



B 



C 



n 



1 mm (var 1) 



w mm (var w) 



r 

 a (var a) 



29 

 9-31 (11-789) 

 6-82 (6-243) 

 0-951 

 0-7277 (0-00186) 



5-01 (16-285) 



3'53 (7-37) 



0-994 



0-6727 (0-00045) 



10 



5-42 (2-813) 



4-19 (i-93) 



0-981 



0-8283 (0-00321) 





Table 



16 





Statistics of length (1) and maximum width (w) of n pedicle valves of Palaeoglossa attenuata 

 (J. de C. Sowerby) from the Meadowtown Beds (A), the Rorrington Beds (B) and the Betton 



Beds (C) 



ABC 



n 32 36 23 



1 mm (var 1) 10-76 (28-081) 5-8 (11-584) 5-09 (1-589) 



wmm(varw) 7-67 (17-835) 4-23(6-518) 3-23 (0-67) 



r 0-982 0-984 0-918 



logel ( var log e l) 2-2667(0-2173) 1-6098(0-2958) 1-5978(0-0594) 



log e w (var log e w) 1-9051(0-2646) 1-2872(0-3104) 1-1431(0-0618) 



r e 0-985 0-9871 0-925 



a (var a) 1-1036(0-0012) 1-0244(0-00079) 1-0203(0-00718) 



Table 17 



Statistics of length (1) and maximum depth (th) of 9 pedicle valves of Palaeoglossa attenuata 

 (J. de C. Sowerby) from the Meadowtown Beds 



1 mm (var 1) 10-34 (9*89) 

 th mm (var th) 0-77 (0-087) 



r 0-964 



a (var a) 0-094 (0-00008) 



Table 18 



Statistics of length (1) and length of ventral pseudointerarea (pi) of 7 pedicle valves oi Palaeoglossa 

 attenuata (J. de C. Sowerby) from the Meadowtown Beds 



1 mm (var 1) 13-5 (66-oo) 

 pi mm (var pi) 1-43 (0-789) 



r 0-909 



a (var a) 0-1093 (0-00041) 



