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BRITISH DEVONIAN BRACHIOPODA. 



Orthis granulosa. I was able to examine only one valve of this so-termed species, and therefore cannot 



feel certain as to its specific value. 

 Productus scabricidus, determined from imperfect casts in the Upper Devonian Grits of North Devon. 



— longispinus. Some casts from the Upper Devonian Grits of Barnstaple have with uncertainty 



been referred to this species. 



The following are very doubtful so-termed species, and are here merely quoted for the 

 sake of reference, as it has not been possible to refer them with certainty to any of 

 the others. 



Spirifera canalifera, vel aperturata. I have seen no specimen which could with certainty be referred to 



this well-known Devonian species. An uncertain fragment of a Spirifer from 



Linton was so identified by Prof. Phillips. 

 — mesomala, Sp. obliterata, Sp. megaloba, and Sp. rudis, Phillips, appear to me to have been 



established from undeterminable fragments or casts. 

 Jthynchonella triangularis. Sow., from Plymouth, T have never seen, but is no doubt a synonym of some 



of those already recorded — M'Coy states of acuminata. 



— subdentata has not turned up ; it is probably a synonym of some of the others. 



— sphcerica. I believe this to be a Silurian, and not a Devonian shell. 

 Strophomena persarmentosa has been made out of a distorted undeterminable cast. 



— semicircidaris and plicata are also very uncertain. (Any how, it is cot the Silurian species 

 originally so named by M'Coy.) 

 Productus interruptus is probably a Carboniferous, and not a Devonian shell. 



From the above review it is evident that not many more than seventy British 

 Devonian species of Brachiopoda have been hitherto discovered. Of these about eighteen 

 are also recorded from the Carboniferous period ; or, in other words, fourteen or fifteen 

 appear to be common to the Upper Devonian and Carboniferous, while eleven or twelve 

 may be common to the Middle Devonian and Carboniferous. These statements or num- 

 bers must, however, be taken as being as nearly correct as the present state of our 

 information will admit. The following Table shows at a glance what are those species 

 which appear to be common to the Carboniferous, Upper Devonian (or Marwood, Pilton, 

 and South Petherwin series), and Middle Devonian (such as that of the neighbourhood 

 of Torquay, Newton Abbot, Ogwell, Dartington, Plymouth, &c), and the Lower 

 Devonian (of Looe, Meadfoot, and Linton). 



