6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



the ptychoparioid trilobites, so common in the late Lower Cambrian 

 deposits of the Appalachian and Cordilleran provinces. No fragments 

 referable to the Agnostids were observed. 



Even though the Acimetopus bilobatus faunule has few, if any, 

 species in common with the Elliptocephala asaphoides assemblage, 

 the latter is still the Lower Cambrian fauna of North America which 

 it resembles most closely. Possibly all the species, and many of the 

 genera, are different, but the same families are represented, approxi- 

 mately in the same relative abundance : the Eodiscidae and Olenel- 

 lidae are common, Bonnia and Kootenia are rare in both cases. 

 The Acimetopus bilobatus faunule shows far less affinity with the 

 late Lower Cambrian fauna of the Pacific province (era tonic facies 

 of Lochman and Wilson, 1958), which is characterized by the abun- 

 dance of Ptychoparioids and Bonnia, frequently includes Kootenia, 

 Protypus, and Prozacanthoides, and also Pagetia and Pagetides. The 

 resemblance is not very close either with the typical late Lower 

 Cambrian fauna of the Acado-Baltic province (eugeosynclinal facies 

 of Lochman and Wilson), chiefly characterized by the Protolenidae, 

 where the Eodiscids are represented both by oculate (Hebediscus), 

 and blind genera {Calodiscus, Cobboldites, Serrodiscus). In North 

 America faunules of this type are known from Massachusetts and 

 eastern Newfoundland (Hutchinson, 1962). The evidence favors the 

 reference of the new faunule, like the Elliptocephala asaphoides 

 assemblage, to an "intermediate realm" (Lochman and Wilson, 

 1958) between the cratonic and eugeosynclinal sedimentary prov- 

 inces. 



Through the courtesy of Mr. A. W, A. Rush ton, the writer was 

 able to examine specimens and photographs of a remarkable new 

 faunule discovered in the Purley Shales of Warwickshire, England. 

 The faunule includes several new species of Eodiscidae, of which two 

 belong to new genera, one is a Serrodiscus remarkably similar to 

 Serrodiscus subclavatus described herein, and another is definitely 

 referable to Acidiscus, closely resembling Acidiscus hexacanthus in 

 possessing two pairs of marginal cephalic spines. The Eodiscidae 

 in the Purley Shales are associated with Ellipsostrenua and Condy- 

 lopyge. Even though all the previously described species of this 

 agnostid genus occur in the Middle Cambrian, the remainder of the 

 faunule is suggestive of a late Lower Cambrian age. A fairly close 

 time equivalence of the two faunules may be indicated by the 

 presence of closely related Eodiscidae. 



