72 me. s. s. buckmax ox [vol. lxxri, 



in Dorset, but they are not well preserved ; it is so characteristic 

 of the Wiirtemberg Middle Lias as to have given the name 

 Numismalismergel to a large part of Lias y. Eh. thai 'i a is an 

 unmistakable form : it occurs at several places in the Severn 

 Valley, but is absent from Radstoek, very doubtful for Dorset, is 

 common in Normandy, is absent from Wiirtemberg. The difference 

 in the distribution is to be noted, as raising suspicion whether the 

 strata yielding Cincta and the Rhynchonella are of quite the same 

 date. The absence of the JRhynclionella from Wiirtemberg might 

 be taken as distribution failure, but its absence from Somerset, 

 though it occurs a few miles to the north in Gloucestershire and 

 reappears to the south in Normandy, is the chief point, for 

 brachiopods flourished at Radstoek in the Middle Lias. 



Rliynchonella rosfellata might be expected to agree in range 

 with JRh. thalia. but it does not: it is common in Wiirtemberg, and 

 fails in Normandy : it is absent from Radstoek, and very doubtful 

 for Dorset. 



Assistance in investigating the position of the brachiopod fauna 

 Avould be expected from Quenstedt' s ' Der Jura.' He has there, 

 however, in the Middle Lias (Lias y) an ammonite sequence which 

 has long puzzled me. As it may be a source of trouble to others 

 I am tempted to transcribe the essential part of his table (Table II), 



Table II. — Succession in Lias (/3, y, pars) according to Quenstedt. 1 



-Dflwasj'kalk . Ammonites dascei, striatus, lineatus, maculatus. 



Ammonites jamesoni. 



g, t c Ammonites ibex, polymorphus, maugenestii. 

 '-3 s A. valdani, masseanus, striatus, pettos. 

 jj ^ Terebratula numismalis, rimosa. 



i5 Ammonites centauries, natrix, heterophyUus, 

 latcecosta, bronnii, caprarius. 



c ■ ■<• i i ( Spirifer verrucosus, Terebratula curvieeps, calcicosta. 



1 I Ammonites nodogujas, tat/lori. 



Gri/pheea obliqua (cymbium) . 



Ravicostatenbank. A. raricostatus, armatus. 



especially as it can now be seen that his error is. in part at any 

 rate, explicable as due to that faunal repetition of Upionia which 

 I have mentioned above : in fact, his error becomes, to a certain 

 extent, evidence in support of the surmise made in my former 

 paper. 



If the part in Table II relating to the ammonites of the Rostige 

 Kalkmergel were to be turned the other way about, it would give 

 more nearly the sequence set forth in my paper. Oppel who, as 

 his ' Juraformation ' shows, was a genius in identification of speci- 

 mens and in correlation of strata, is quite opposed to Quenstedt : 

 he gives the following sequence : — 



1 XV, 1, Table facing p. 293 



