272 DE. A. E. TRUEMAN OX THE [vol. lxxiv, 



appear in the young of Liparoceras clieltiense at a diameter of 

 10 mm., they are not present in B. becliei until twice that diameter. 

 Other specimens found at Battledown, apparently of this same 

 lineage, show -post- clieltiense stages in which the whorl is more 

 slender, the ornament finer, and the tubercles generally paired. 

 This latter character distinguishes L. clieltiense from the finelv- 

 ornamented sphaerocones of the Beclieiceras series. 



Liparoceras zietexi (Quenstedt). 



Ammonites striatus zieteni Quenstedt (4. pi. xxviii. figs. 1 & 2). 

 Dimensions of figure : — 



Diameter. Whorl height. Whorl thickness. Umbilicus. 



64 mm. 50 per cent. 64 per cent. 22 per cent. 



This presents a similar stage to L. obtusinodiun, but differs in 

 the greater arch of the periphery. 



Liparoceras heptangulare (Young & Bird). 



(Refigured, 1, vol. ii, No. 108.) 



This ammonite has a more slender whorl than L. clieltiense ; 

 the strongly-arched periphery may indicate a connexion with 

 L. zieteni. 



Liparoceras tiaea, sp. no v. (PI. XXI, tigs. 1 a & 1 b ; text- 

 fig. 4 d, p. 270.) 



Compare Ammonites henleyi A. d"Orbigny (3, pi. lxxxiii). 



Dimensions of holotype : — 



Diameter. Whorl height. Whorl thickness. Umbilicus. 



63 mm. 41 per cent. 57 per cent. 29 per cent. 



Stout whorl, evolute, with prominent unpaired tubercles (20/14) 

 united by strong folds, dividing at the outer tubercles into two or 

 three flattened ribs which cross the periphery. 



Irregular longitudinal striation very marked. 



Suture has a deep external lobe, divided hj a high median saddle ; 

 first lateral lobe wide. Sutural elements very deeply undercut 

 (text-fig. M p. 270). 



This species, undoubtedly a Liparoceratid, differs from those 

 previously considered in combining coarse ornament with an evolute 

 form and very complex sutures. 



The type-specimen was collected by Mr. L. Richardson in the 

 Yellow Lias (hemera of Beaniceras), during excavations for a 

 bridge at Manor Farm, Gotherington, near Cheltenham. 



Liparoceras pseud ostriatum, sp. nov. (Fig. \f, p. 270.) 



Compare Mgoceras striatum Wright (8, pi. xlii, figs. 1 & 3). 

 Dimensions of type-specimen : — 



Diameter. Whorl height. Whorl thickness. Umbilicus. 



100 mm. 47 per cent. 65 per cent. 16 per cent. 



