176 



digits. The suiieidor lateral lobe is small, it has five or six long tooth- 

 like lateral digitations on its outer, three or four on its inner side, and 

 bifurcates into two terminal branches ; the inferior lateral lobe is long 

 and slender, with several narrow digitations on the Hides, and a bifurcate 

 termination ; the auxiliary lobe is small ; the dorsal saddle is large, 

 but is not sufficiently exposed for accurate description ; the lateral saddle 

 is very large, occupying two-thirds of the sides of the whorl, it has 

 two large terminal folioles, and two lateral folioles, with four or five 

 lobules in each. 



Affiyiities and Differences. — In the quadrate outline of its whorls and 

 its straight simple ribs it resembles A. Valdani, d'Orb. ; and the terminal 

 tubercle on its ribs likens it in form to A. perarmatus, Sow. ; whilst the 

 form of the lobes and saddles, and the median ridge on the back 

 distinguish it from both. It is very distinct from the other two species of 

 keelless Arietes, and has no affinities with the keeled species of that 

 group, the absence of the dorsal sulci affording a reliable diagnostic 

 character. 



Locality and Stratigraphical Position. — The large specimen was collected 

 in the zone of Ammonites obtusus, near Bredon, during the construction 

 of the Bi'istol and Birmingham railway. The smaller specimen was 

 obtained from the same zone at Darlingscott, near Shipton-on-Sto\ir, and 

 given me by my friend John Kirshaw, Esq., of Warwick. I have found 

 one or two small specimens in the Lower Lias of the Vale of Gloucester, 

 and my fi-iend, R. Etheridge, Esq., F.G.S., collected a specimen from 

 the railway cutting, at Horfield, near Biistol. 



Ammonites Sauzeanus is a very rare Ammonite in France, M. d'ORBiGNY 

 states that he had seen only two specimens of this singular species, which 

 were collected from the Gryplicea arcuata beds of the Lower Lias, by 

 M. BoucAULT, at Champlong, near Semur, (Cote d'Or,) where it is very rare. 



Ammonites Turner:, Sowerhy. (PL 2, fig. 4, a, h.) 



Ammonites Turneri, Sowerhy, Mineral Conchology, tab. 452, vol. v., 

 p. 75., 1825. 



Shell discoidal, depressed, strongly carinated, with a deep narrow sulcus 

 on each side of the keel ; whorls costated, with 42 strong, simple, straight 

 ribs, which bend suddenly forward near the back, each rib thickened at 

 the angle ; whorls one-half involute, inner volutions well exposed ; 

 aperture oblongo-quadrate. 



Dimensions. — Transverse diameter 4J inches ; height of the aperture 

 1^, width 1^*5 inches; amount of involution nearly one-fourth of the 

 whorl. 



