part 4] EVOLUTION OF THE LIPABOCEBATJ U.K. 



Fig. 10. — Sutures of Amblycoceras spp. 



283 



50 mm. 

 A. dissotypum 



(Lincoln). See 

 PI. XXIII, fig. 1. 



b 



18 mm. 



A. crescens 



(Lincoln). See 



PI. XXIV, fig. 1. 



30 mm. 



A. brevilobatvm 



(Leckhampton). 



See PL XXIV, 



fig. 3. 



3*5 mm. 



(The same. 



2 mm. 



(The same.) 



E. OlSTOCEKAS. 



Oistoceras omissum (Simpson >. (PI. XXV, tigs. 2a-2h; text- 

 fig. 11, p. 284.) 



Refigured, 1, vol. i, No. 27. 



Compare.!, macidatum angulation Quenstedt (4, pi. xxxiv, figs. 11 & 12). 



Dimensions of figure (in 1. No. 27) : — 



Diameter. Whorl height. 'Vliorl thickness. Umbilicus. 



28 mm. 25 per cent. - o'l per cent. 54 per cent. 



