﻿200 # DE. A. V AUG HAN ON THE PAL^EONXOLOGICAL [May 1905, 



Fauna : 



Productus aff. scabriculus crowds the beds. 



(The form common in the Avon section is better described 

 as a scabriculate variety of Pr. costatus.) 

 Orthotetes and Productm aff. Cora are apparently not uncommon. 



Note. — ]\£y w hole knowledge of this horizon in the Avon section is derived 

 specimens preserved plentifully in local collections. 



Analysis of Stoddart' s paper dealing with the Palseontological 

 Sequence in the Avon Section. 1 



(Solely with reference to the Corals and Brachiopods.) 



The fossils cited in that paper will, for convenience, be designated by different 

 letters, according as they fall into one or other of the following classes : — 



A. Those represented in the collection under the name cited in the paper 

 and so localized as to suggest the horizon at which they are recorded. 

 (With one or two exceptions the horizon is stated very broadly ; as, for 

 example, Black Rock, Lower Limestone-Shales, Middle Limestone, etc.) 

 C. Those unrepresented in the collection (at least so far as the particular bed 

 under consideration is concerned). 

 The class will be subdivided into : — 



C 1. Those which may be accepted as really occurring at the horizon 

 stated. 



(Here I include those fossils which are usually identified correctly 

 in the collection, or could not easily be mistaken for any of the 

 other fossils known to occur at the particular horizon.) 

 2. Those which should be rejected as erroneous determinations. 



(Here I include all fossils which are habitually determined erro- 

 neously in the collection.) 



The fossils are grouped into the zones that I have suggested ; the number in 

 front of the name is that employed by Stoddart to denote the particular bed in 

 which the fossil occurs ; the letter after the name has the meaning explained 

 above ; and I append the name under which the fossil is recorded in my own 

 work. 



In some cases, the alteration in name consists merely in the employment 

 of more recent generic nomenclature; in others it consists in more accurate 

 specific identification ; while in several, Stoddart's determination undoubtedly 

 was entirely erroneous. 



The names given in inverted commas are those cited by Stoddart, and they 

 are here considered to denote the fossils so named by him in the Stoddart 

 Collection : as, for example, ' Ehynchonella pleurodon,' in the sense implied by 

 Stoddart (that is, Pugnaw pugmis), is not known to occur in the Mo dio la-Zone ; 

 whereas the common Ehynchonella in this zone is called ' Betzia radialis' by 

 Stoddart, and would probably have been passed by Davidson as a variety of 

 Ehynchonella pleurodon . 



MoDiGLA-Zoim. (Beds 1 to 5.) 



(2 & 4) ' Athyris Eoyssii ' ; A ; Cliothyris Eoyssii. 



' (2) ' Spirifera rko?nboidea' ; C2; probably indicates a Spiriferid of 



considerable trans versify. 

 (2) ' Betzia radialis' ; A ; Ehynchonella mitcheldeanensis. 



1 Proc. Bristol Nat. Soc. n. s. vol. i (1875) pp. 318 et seqq. 



