28 MOLLUSCA FKOM THE GREAT OOLITE. 



{c.) LiM^\ Lvcm^sis, JD' Ordi^n;^. Tab. Ill, fig. 4. 



Lima Ltjciensis, D'Orbigny. Prodrome de Paleontologie, p. 313, 1850. 



Testa plano-convexd, oblique elongatd, umbonibus acutis depressis, approximatis, auriculis 

 magnis subcequalibus ; costis (10 aut 11) magnisplicatis, interstitialibus conformibus. 



Shell compressed or rather convex, obliquely elongated, umbones nearly straight, 

 pointed, and approximated, auricles large, nearly equal and costated longitudinally, the 

 anterior auricle corrugated and gaping. Costae upon the back of the shell (10 or 11) 

 large, plicated, rounded, with large conformable interstitial spaces. 



This species has less obliquity than is usual with the Lima, and this character will 

 always serve to distinguish it bom. Lima angusta, Buvignier, t. 18, f. 27, which occurs in the 

 middle portion of the Inferior Oolite in Gloucestershire, the character of the costae in that 

 species is very similar but more curved, the shell is always very obhque, its anterior side 

 or lunule being concave. Compared with Lima siibstriata, Goldfuss, our species is much 

 more elongated, has fewer costge, and has not the distinctly raised murications or plicae 

 by which the costae of that species are ornamented. It is somewhat rare, but occurs in 

 several of the shelly beds. 



Locality. The Minchinhampton district. 



{d.) Lima gibbosa. Sow. Tab. Ill, fig. 7, 7 a. 



Lima gibbosa, Sow. Min. Con., t. 152, 1817. 



— — Bronn. Leth. Geog., 213, t, 19, f. 11, 1851. 



— — — Index Palseont., p. 645, (not Goldf. ?) 



Testa convexd ovato-subobliqud, elongatd, fornicatd, umbonibus magnis approximatis, 

 dor so costato ; costis (11 — 13) elevatis acutis, canalibus conformibus; striis ienuissimis, 

 transversis decussatis. 



Shell ovate, shghtly oblique, convex, elongated, ribbed, umbones large and contiguous, 

 back of the shell with acute, elevated costae from 11 to 1 3 in number, with conformable 

 interstitial spaces ; the entire surface has very fine transverse striae. 



The sides of the shell are destitute of costae, the .smooth surface being about equal in 

 extent to that which is costated. This species is perfectly distinct from the Lima gibbosa 

 of Goldfuss, which is more obhque, the costae are curved, they extend even upon the 

 posterior sides of the valves, and their number is more than twice as great as in our own 

 or Sowerby's species. In the shelly beds of the Great Oolite it occurs very rarely in 

 single valves, and never equaUing half the size which it attains in the Inferior Oolite, but 

 in the seams of clay which are associated with Stonesfield .slate, casts are found of the 

 full dimensions, and with the valves in apposition. 



Localities. Minchinhampton Common; Ancliff, Wiltshire. 



