THE GEOLOGICAL AGE OF CENTRAL A^T) WEST CORXWALL. 177 



2. B. bisulcalm — Polporro and Fowey, McCoy. 



3. 7A s/;.— Gribbou, St. Columb, &e., Peach 1844. 



4. Conularia quadrisulcata — Cxribbeii, Peach 1844. The specific 



tieterminatiou may probably be incorrect, but the 

 genus ranges from Lingula Flags to Upper Carhoniferous. 



5. Tentaculites ornatus — St. Veep, Peach 1850. This species is 



a typical Silurian one, its range, according to Murchison, 

 being from Caradoc to Wenloclc. The genus is for the 

 most part Silurian also. We have placed it among the 

 Pteropoda, following Nicholson, but many would still 

 regard it as an Annelid. 

 Evidently the Heteropoda and Pteropoda are rather more 

 Silurian than Devonian. 



CEPHALOPODA. 



1. Orthoceras cylindraceum — Fowey, Peach 1344. If this be 



rightly named, it is a Devonian species. 



2. Orthoceras hullatum — Polperro, Couch 1850. Ranges, accord- 



ing to Murchison, from Llandovery to Ludloio. 



3. 0. striatulum — Fowey, Peach 1844 ; St. Austell Bay and St. 



Veep, McCoy. Devonian. 



4. 0. sp. — Pope Haven near Blackhead. Fine specimen found 



by T. Clark and J. H. Collins, and now in the Trui-o 

 Museum. 

 The following are in j\[us. Poy. Geol. Soc. Cornwall, Penzance. 



5. 0. ibex — Punch's Cross, McCoy ; range Caradoc to LudlouK 



6. 0. Liulense — Coombe Haven, Fowey. The characteristic 



and typical Ludlow species. 



7. Specimens of 0. also from Whitehouse Ferry, Pridiuoutli, 



Punch's Cross, Polruan, St. Veep, Coombe Haven, 

 Looe, Ethy Wood and Lerrin. 



8. Goniatites inconstans — Fowey, Peach 1844. Devonian. 



9. Bactrites gracilis ( 0. gracilis) — Blackhead, according to Mur- 



chison {^Sil. 5th Edt. '211), who gives it nevertheless us 

 Lower Devonian. Portlock called it Caradoc. 



The Cephalopoda tell the same tale, indistinct though it be, 

 as the gasteropoda, etc. 



