parti] OF THE SHALES-WIT11-' BEEF.' S3 



of X. planicosta, as figured by F. von Hauer. 1 The latter, how- 

 ever, has a comparatively small first lateral lobe, whereas the most 

 striking feature of the development of the suture-line in Micro- 

 deroceras is the width of the principal lobe. Xiplieroceras, then, 

 may be a simplified branch of the same stock, rather than con- 

 nected with Agassiceras, as I at one time thought probable. 3 



In North-Western Europe : that is, outside the Mediterranean 

 province, Deroeeratids, unfortunately, are exceedingly rare in pre- 

 birchi times. Three fragmentary specimens of a form comparable 

 to Ammonites circumdatus (Martin) Kevnes 3 from Welford Hill 

 (Gloucestershire) in the Tomes Collection (B.M. C 17265-67) are 

 the only British examples that I have seen. The age of this form, 

 however, given as ' buehlandi ' in Keynes, is doubtful. 



JEctocentrites adnethicum (Hauer) is of Sinemurian age, and 

 has nothing to do with the genus Anisoloboceras Trueman ■* or 

 the family Liparoceratidse. It may also be added here that 

 Ectocentrites still occurs in the Sulciferites-Arnioceras shales 

 of Spezia. 



(J) Summary of New Names. 



Metacymbites, gen. nov. (p. 76). 



Genotype : Ammonites centriglobus Oppel. 

 Protocymbites, gen. nov. (p. 77). 



Genotype: P. w.ehxeri, nom. nov.= Arietites semicostulatus W iihner 

 no n Reynes sp. 



Paracaloceras, gen. nov. (p. 77). 



Genotype : Arietites coregonensis (Sowerby) Wahner. 

 Pseumetomoceras, gen. nov. (p. 77). 



Genotype : Arietites abnormilobalus Wahner. 

 Htpasteroceras, gen. nov. (p. 84). 



Genotype : Asteroceras ? ceratiticum Fueini. 



Slatterites, gen. nov. (p. 87). 



Genotype : Mgoceras slatteri Wright. 

 Agassiceras beynjesi, nom. nov. (p. 72). 



^Ammonites multicostatus Sowerby, var. spinaries Quenstedt, in 

 Reynes. 



JEtomoceras decipiexs, nom. nov. (p. 72). 



= Ammonites multicostatus Sowerby in Simpson= ''Agassiceras sp.' 

 in Buckman. 



Arietites psevdoboxkardi, nom. nov. (p. 76). 



= Arietites bonnardii (Wright non A. d'Orbigny). 



1 ' Ueber die Cephalopoden aus dem Lias der Nordostlichen Alpen ' 

 Denkschr. K. Akad. Wissensch. Wien, vol. xi (1856) pi. xvi, fig. 6 ('A. plani- 

 costatus' Sowerby). 



2 Geol. Mag. 1919, p. 175. 



:t ' Monographie des Ammonites ' 1879, pi. xxviii, figs. 19-22. 

 4 'Evolution of the Liparoceratidaa ' Q. J. G. S. vol. lxxiv (1918-19) 

 p. 263 & p. 286. 



g2 



