part -1] 



CAMBRIAN HORIZONS OF COM LEY. 



371 



occur in all the Lower Cambrian horizons Ac 4 to Ad, and also in the Middle 

 Cambrian horizons Ba 1: Ba„, Ba 3 , and ~Bb l -. that is, throughout the whole of 

 the Protolenus-Callavia Fauna and of the Paradoxides-celandicus Zone, and 



in the Paradoxides-tessini Zone. 



The fragments assigned to Callavia, together with Helen ia 

 cancellata and the connexions between the individual faunas of 

 horizons Ac, to Ac,, serve to link them into one group, which has 

 been called the Protolenus-Callavia Fauna l of Comley. 



Of the species recorded, the following are found or represented 

 in the Lower Cambrian of the Atlantic Province of North America, 

 a considerable proportion being included in Dr. Matthew's Proto- 

 lenus and Etcheminian Faunas. 



Species of the Protolenus-Callavia Fauna of Comley (Horizons Acj to Ac 5 ) 

 which are represented in the Atlantic Province of North America : — 



Microdiscus altleborensis. 



Microdiscus bellimarginatus. 



Microdiscus lobatus. 



Microdiscus speciosus. 



Strenuella platycephala. 



Strenuella salojnensis. 



Protolenus latouchei. 



Micmacca (?) ellipsocephaloides var. 



spinosa. 

 Callavia callavei. 

 Wanneria (?) sp. 



Micromitra (Paterina) labradorica. 



Obolelia atlantica var. comley ensis. 



Obolella atlantica var. transversa. 



Hyolithus (Orthotheca) bayonet. 



Hyqlithellus micans. 



Helenia cancellata. 



Helcionella rugosa var. comleyensis. 



Leperditia (?) dermatoides. 



Escasona (?) sp. 



Bradoria (?) sp. 



Microdiscus a nnio. 



Horizon Ac. The Strenuella Limestone of Comlev. 2 



Obolella atlantica var. transversa. 



Liiu/ulella viridis. 



Hyolithus (Orthotheca) bayonet var. 



striatus. 

 Hyolit.hellus micans. 

 Salopiella obliqua. 



Microdiscus lobatus. 

 Microdiscus speciosus. 

 Strenuella parva. 

 Strenuella platycephala. 

 Strenuella salop>iensis. 

 Callavia cf. callavei (fragments). 



The relations between this fauna and those of contiguous 

 horizons are discussed above (p. 370). 



Horizon Ac 5 . Protolenus Limestone. 



Micromitra (Paterina) labradorica. 



Obolus parvulus. 



Lingulella viridis. 



Hyolithus crassus. 



Hyolithus sculptilis. 



Hyolithus (Orthotheca) bayonet. 



Salterella (?) bella. 



Salterella (?) striata. 



Hyolith ell us micans. 



Helenia, cancellata. 



Helcionella cingulata. 



For discussion of the relationship 

 (p. 370). 



Latouchella costata. 

 Latouchella striata. 

 Microdiscus comleyensis. 

 Microdiscus lobatus. 

 Microdiscus speciosus. 

 Protolenus latouchei. 

 Protolenus morpheus. 

 Mohicana clavata. 

 Mohicana lata. 

 Callavia cf. callavei (fragments). 



of this fauna to those below, see above 



1 Cobbold, 19116, p. 297. 



a The faunas of horizons Ac ( and Ac. were combined under the one heading 

 ' Lobatus Group ' in Cobbold, 1911 b, p. 297. 



