Vol. 5 i.] 



HEMERjE. 



bradfordeiisis. 4. Bh. cynomorpha, sp. n 



OF THE MID-COTTESWOLDS. 



449 



Murchisoncs. 



scissi. 1 

 opalini. 



aalensis. 



Moorei. 



Dumortierice. 



7. Bh. Brasili, 

 ep. n. 



6. Bh. sp. 



Bh. subangulata 



5. Bh. aff. Wcigandi. 



1. Bh. f «**««»■. 



[ cynocephala. 



(Bh. cynica) \ 



Bh. cynica, sp. n. 



2. i?A. cynoprosopa, sp. n. 



Rhynchonella Stephensi, Davidson =? cynocephala. (Richard). 

 (PL XIY. fig. 1.) 



1810. Terehratula cynocephala, Richard, Bull. Soc. geol. France, vol. xi. pi. iii. 

 figs. 5 a-d, p. 263. 



1877. Rhynchonella Stephani, Davidson, ' Brach. Inf. Ool.,' Proc. Dorset Nat. 

 Hist. & Ant. Field-Club, vol. i. pi. iv. fig. 13. 



1877. Rhynchonella cynocephala, Davidson, ibid. pi. iv. fig. 16. 



1878. Rhynchonella Stephensi, Davidson, ' Monogr. Brit. Fossil Brachiopoda,' vol. 

 iv. p. 220, Pal. Soc. Suppl. pi. xxvii. fig. 20. 



1882. Rhynchonella cynocephala, S. Buckuian, ' Bracb. Inf. Ool.,' Proc. Dorset 

 Nat. Hist. & Ant. Field-Club, vol. iv. p. 42. 



A Rhynclionella — one of the pugnaces. The mesial fold narrow, 

 fairly elevated, generally biplicate, its sides convergent. 



The history of this species is worthy of particular notice. In 1877 

 Davidson figured a 3-plait form by the name cynocephala ; but at 

 the same time he depicted a young shell of the 2-plait form by the 

 name Rhynchonella Stephani. In 1878 he figured the same little 

 shell as Rh. Stephensi. At that time he had only a few specimens to 

 examine ; but subsequently I discovered the species in some quantity ; 

 and after an examination of the type Stephensi, kindly put into my 

 hands by Davidson, I was able to convince myself that Stephensi was 

 only the young of his 'Rh. cynocephala' — an opinion set forth in my 

 paper in 1883 (op. cit.). I also noticed at the time that the Dorset- 

 Somerset specimens differed from the Cotteswold forms called ' Rh. 

 cynocephala' an observation fully confirmed by subsequent collection 

 of larger series. It then became necessary to determine which form 

 agreed with the French fossils ; because the Dorset specimens were 

 being given the name Stephensi to distinguish them from the Cottes- 

 wold forms. The result showed that the Cotteswold forms required a 

 new name, while the Dorset specimens (Stephensi) were really very 



1 The time when Tmetoceras scissum (Benecke) lived, rather later than 

 opalinus, rather earlier than Murchisonae. 



2i2 



