106 SHELVE DISTRICT 



appropriate, therefore, to recognize the Shelve sample as a new subspecies of R. 

 horderleyensis. 



Table 73 



Statistics of length (1) and maximum width (w) of 7 brachial valves of Reuschella horderleyensis 



carinata subsp. no v. 



1 mm (var 1) io-oo (28-5) 



w mm (var w) r3'73 (4 I-I 99) 



r 0-993 



log e l (var log e l) 2-1772 (0-2506) 



logew (var log e w) 2-5206 (0-1976) 



r e 0-995 



a (var a) 0-8879 (0-00155) 



Table 74 



Statistics of length (1) and thickness (th) of 7 brachial valves of Reuschella horderleyensis carinata 



subsp. nov. 



1 mm (var 1) 11-31 (20-841) 

 th mm (var th) 1-74 (0-556) 



r o-8n 



a (var a) 0-1633 (0-00182) 



Table 75 



Statistics of length (1) and length of brachiophore bases (lc) in 9 brachial valves of Reuschella 



horderleyensis carinata subsp. nov. 



1 mm (var 1) 12-69 (16-259) 

 lc mm (var lc) i-8i (0-196) 



r 0-883 



a (var a) 0-1098 (0-00037) 



Table 76 



Statistics of length (1) and maximum lateral extension (w) of the brachiophore bases of 8 brachial 

 valves of Reuschella horderleyensis carinata subsp. nov. 



1 mm (var 1) 1-96 (0-103) 



w mm (var w) 3-99 (0-373) 



r 0-771 



a (var a) 1-9052 (0-24495) 



Family HETERORTHIDAE Schuchert & Cooper 1931 



HETERORTHIS Hall & Clarke 1892 



Heterorthis sp. 



(PI. 17, figs. 10-14) 



Diagnosis. Small, semi-elliptical, piano- to concavo-convex Heterorthis with 

 parallel-sided, bilobed ventral muscle scar 42% as long as the pedicle valve and a 

 simple, median, plate-like cardinal process. 



