24 TYPE AMMONITES— VI June 



Fontannesia in Sonninian 

 Dumortieria in Dumortierian 



I Eudmetoceras in Sonninian 

 i Parammatoceras in Ludwigian 

 Hammatoceras in Dumortierian 



Defossiceras in Liparoceratan 

 Euagasstceras in Agassiceratan 



Angulaticeras in Oxynoticeratan 

 Schlotheimia in Schlotheimian 



The re-appearance of oxynotes in the Polymorphitan Age, after 

 absence during the Deroceratan and presence in the prior Oxynoticeratan 

 Age, is not necessarily congruous with the above cases. The genera 

 involved are highly catagenetic ; their general similarity in shape 

 indicates degeneration along similar lines of decline (convergence), not 

 necessarily intimate relationship. More strikingly is this brought out 

 in the Cretaceous species of oxynotes, which have for long been placed 

 in the genus Oxynoliceras, as if they were actually related to the Lower 

 Lias (Oxynoticeratan Age) genus. Such relationship is quite out of the 

 question — the gradual decline of distinct and quite unrelated forms to a 

 general oxynote shape is now recognised as a usual phenomenon of 

 extreme senile decay. 



Ammonoid Species named pringlei : During the last two years 

 the trivial name pringlei has been applied independently by three 

 different authors to three different Ammonoids of the Portlandian- 

 Kimmeridgian deposits. The first in order of date is Wheatleyites 

 pringlei, Pruvost, 1924 (Pringle and Pruvost, Serie portlandienne du 

 Boulonnais ; Comptes rend. Acad. d. Sciences, clxxviii, pp. 399, 400) : 

 this, however, is a nomen nudum, for there is neither description nor 

 figure. 



The next name is Shotoverites pringlei, S. Buckman, April, 1925 

 (Type Amm., PI. DLXII), the holotype of which is a fairly large specimen 

 obtained by Mr. J. Pringle at Shotover Brickyard, near Oxford. 



Then in June, 1925, are published figures and descriptions of 

 Wheatleyites pringlei, Pruvost (Ann. Soc. geol. du Nord, xlix, p. 209, 

 PI. H, figs 1-7). 



The last in date is Pallasiceras pringlei, Neaverson, 1925 [Jan., 

 1926 ?], Amm. Upper Kimm. Clay ; University of Liverpool, p. 20, 

 PI. I, L 10). 



Shotoverites pringlei has a suture-line formula as follows : 48, 40, 

 46, 22, Li being decidedly trilobulate and narrow-stemmed. 



Wheatleyites pringlei, Pruvost. The author has not selected any 

 holotype, and, as seven specimens are concerned, which may or may not 

 be conspecific, it is necessary to choose one. Therefore as lectotype is 

 taken the example depicted in figs, i, la-ic, concerning which there is 

 most pictorial information. The suture-line formula of this form comes 

 out, from the lobe-line depicted, as SI. (fig.) 32, 44, 42, 22. The difference 

 between this formula and that of Shotoverites pringlei is not great, but 

 Li is different in shape — it is not markedly trilobulate and is broad- 

 stemmed, somewhat oblong. There might reasonably be hesitation in 



