THE GEOLOGICAL AGE OF CENTBAL AND WEST COBNWALL. 183 



according to Murchison, Llandeilo to Wenlock ; it is 

 figured by Davidson he. cif. 



3. 0. sj). This unnamed species has been found at Gorran 



and also in the pebbles of the Budleigh-Salterton beds. 

 Specimens may be seen in the Museum of the Geological 

 Society of Edinburgh. 



4. 0. scotica. This is found at Gorran and in the Budleigh- 



Salterton pebbles (v. remark on Stroph. grandis above). 

 It is given by some writers as a mere variety of 

 0. calligramma, but Davidson, by whom it is figured, 

 he. cit., recognizes it as a distinct species and calls it 

 Caradoc. Good specimens are to be seen in the Museum 

 at Penzance. 



5. Orthis Budhighensis (Dav.) includes specimens which Salter 



referred partly to 0. redu.v of Barrande, and partly to 

 0. testudhiaria. It probably includes most if not all 

 of the 0. testudino/ria {Dalm.), and has also been called 

 0. Peachii. Specimens have been found at all the 

 Cornish localities, from Gorran and Caerhayes to 

 Manaccan ; also in pebbles of a light-grey quartzyte in 

 the Budleigh-Salterton beds, and in the "May" beds 

 of Brittany. According to Davidson it occurs in the 

 "May" beds with 0. Berthoisi and 0. Monnieri= 

 0. Vicaryi. Rocks of similar age in Normandy contain 

 "principally 0. Budhighensis with a few casts of 

 0. Berthoisi''^ (Dav.) Salter, who noticed the same 

 association of 0. Vicaryi {= 0. llonnieri), 0. redux 

 ( = 0. Budleigliensis) and 0. Berthoisi, declared the 

 quartzyte to be of Arenig age both in situ in Brittany 

 and in the pebbles of Budleigh-Salterton. He also 

 gives 0. testudinaria (Balm.)— 0. Budhighensis (Dav.) as 

 Lower Llandeilo. Davidson says the real 0. testudinaria 

 is a characteristic Llandeilo species, but is not sure 

 that it occurs in the Cornish rocks. In describing 

 0. Budhighensis our authority gives its horizon as 

 Caradoc, but in another place gives that of another 

 species wliich occurs with it — 0. Monnieri — as typical 

 Llandeilo, so that it would appear to range into both 

 series. Specimens of the fossil may be seen in the 

 Museums at Jermyn Street, Penzance, and Truro, and 

 like the others it is figured by Davidson he. cit. 



