EXPLANATION OF THE PLATES AND WOOD-CUTS. 



Fig. 2. Astarte compressa. Nearly orbicular, wider than long, flattish, concentrically 

 ribbed; lunette deep, small; beaks small, near the anterior side; edge toothed. 

 Length \\ inch, width 1 inch 5 lines. 



A species very closely resembling this is found at Cross Hands in Gloucester- 

 shire in the inferior oolite. 



Fig. 3, 3 a. Astarte rotunda. Orbicular, concentrically ribbed ; beaks central ; lunette 

 sunk ; margin toothed. Length 2 hues, width the same. 



Nearly like A. elegans (M. C. t. 137, f. 3.), but it is so much imbedded in the 

 stone that its characters cannot be clearly determined. Fig. 3 a. is magnified. 



Fig- 4, 4a. Corbula pecthiata. Trigonal, rounded, gibbose, longitudinally striated, 

 concentrically ribbed ; posterior extremity separated in the form of a small lobe, 

 pointed ; ribs thin, much elevated. Lunette deeply sunk, not defined ; beak in- 

 curved. Length and width nearly equal, from | an inch to an inch. Fig. 4 shows 

 the impression of the hinge-tooth. 



This differs from Corbula hjrata {ant^ Grant, PI. XXL, f. 13.), which is also 

 from Cutch, in having numerous thin striae and thin ribs. It occurs loose and in 

 masses with several other shells in a red limestone. 



Fig. 5. Trigonia Smeeii. Transversely much elongated, posteriorly truncated, con- 

 vex, concentrically ribbed ; the posterior surface distinguished by an obscure 

 ridge, and furnished with twice as many ribs as the other part ; ribs obtuse, sel- 

 dom interrupted ', beaks near the anterior extremity, which is rounded. Length 

 2 inches 5 lines, width 4 inches. The figure is reduced to frds the natural size. 



Fig. 6, 6 a. Tornatella striata. Ovate, pointed, transversely punctato-striated ; one 

 obscure plait on the columella. Height 2^ lines, diameter \~ line. 



Much resembling Phasianella striata (Fitton, in vol. iv. PI. XVIII., f. 15.), but 

 the apparent plait on the columella, if it be not the effect of fracture, distinguishes 

 it. Fig. 6 a. is magnified. 



Fig. 7. Terebratula microrJujncha. Subtetrahedral, rounded, plaited, lower valve 

 nearly flat, plaits angular, 28 or 30, of which about 9 are raised in the front ; beak 

 of the lower valve very small, its aperture inclined inwards, and its sides smooth 

 and sunk. Length 2 inches, width If inch, depth of the valves united 1| inch. 



A large species, distinguished from T. Hobilis (Grant, PI. XXII., f. 14.) by the 

 greater number of plaits. 



Fig. 8. Armnonites Maya. Discoid, convex with a rounded front, umbilicated, radiated ; 

 umbilicus conical, smooth within ; radii rather numerous, slightly elevated 2-, 3- or 

 4-partite, bent over the edge of the umbilicus ; aperture rounded-sagittate with 

 truncated angles. Diameter 7| inches, width of the aperture 3| inches, its length 

 4 inches. 



This is an intermediate species between A. formosus (Grant, PI. XXIII. f. 7.), 

 and A. HervcTji (M. C), a variety of which also occurs with this. Its sides are 

 flatter than in the A. Herveyi, although the front is round, and the ribs less raised. 



Fig. 9. Ammonites calvus. Discoid ; inner whorls two thirds exposed, nearly crossed 

 by rounded ribs, and plaited over their fronts ; outer whorls crossed by prominent 

 rounded ribs, their front rounded, plain ; aperture oval, impressed by the preceding 



