Pit 



I.ASTBA. 



CONCHIFERA. 



203 



r. scalaris. Sowerby, V. pi. 1 4C, p. 490, fi^'. 3. 



A little olongateil ; nearly straif,'lit, aiul sub- triangular ; 

 slightly conipressctl ; beaks obtuse, and nearly central ; car- 

 dinal teeth long and thin ; surface with about twenty very 

 flat, straight, divergent ribs, crossed by fine concentric stria; ; 

 internal margin denticulated. 



The Red, and also tlio Coral Crag, Sutton. 



8. Ve.vericardia cnAMAEFORMis. — Tho Chama-formed 

 Venericardia, pi. LXXXIII. fig. 29. 



r. c/ianiM/ormis. Sowerby, V. p. 145, pi. 49G, fig. 1. 



(Oblong ; convex ; a little acuminated towards tho beaks, 

 which are slightly curved and produced, with about four- 

 teen large, rugged, prominent, distant ribs, with flat, inter- 

 vening furrows. 



The Coral Crag, Sutton. 



4. Vexericardia deltoidea. — The Deltoidal Venericardia, 

 pi. LXXXIII. fig. 34. 



F. (Mtoulea. Sowerby, III. p. 100, pi. 259, fig. 1. 



Deltoidal ; a little oblique ; hinge very strong; surface with 

 about twenty almost smooth, carinated, curved, longitudinal 

 ribs; lunette small and obsolete; internal margin crenated ; 

 hinge remarkably strong. 



The London Clay, Barton and Lyudhurst. 



5. Venericardia acuticosta. — Tho Sharp-ribbed Veneri- 

 cardia, pi. LXXXIII. fig. 32. 



F. carinata. Sowerby, III. p. 106, pi. 259, fig. 2. 



Transversely oblong; gibbose ; beaks very large and ob- 

 tuse ; lunette obsolete ; a little indented below the beaks ; 

 surface with about twenty almost smooth, prominent, curved, 

 carinated ribs ; internal margins denticulated. 



Tho London Clay, Bracklesham Bay ; Stubbington and 

 Barton. 



C. Venericardia globosa. — The Globular Venericardia, 

 pi. LXXXIII. figs. 30, 31. 



V. fflobosa. Sowerby, III. p. 161, pi. 289, upper and 

 middle figs. 



Globular ; beaks rather large and obtuse ; surface with 

 from fifteen to twenty carinated, strong, curved ribs, the ca- 

 rina; being provided with compressed tubercles ; inner mar- 

 gin strongly denticulated. 



The London Clay, Barton and Hordwell. 



T. Venericardia oblonoa. — The Oblong Venericardia, pi. 

 LXXXIII. fig. 2C. 



F. ohlonga. Sowerby, III. p. 162, pi. 289, three lower 

 figures. 



Transversely oblong ; sub-quadrangular ; gibbous ; oblique ; 

 sides unequal ; surface with eleven to thirteen strongly tubcr- 

 culated, curved, distant ribs ; internal margin with large 

 crenulations. 



The London Clay, Barton. 



8. Venericardia orbicularis. — The Oibicular Veneri- 

 cardia, pi. LXXXIII. fig. 27. 



V. orlicu/aris. Sowerby, V. p. 145, pi. 490, fig. 2. 



Orbicular, rather convex ; surface with about sixteen cren- 

 ated, longitudinal ribs ; the intervening furrows concentrically 

 striated ; hinge small. 



The Red Rag, Sutton. 



9. Venericardia senilis. — The Aged Venericardia, pi. 

 LXXXII. fiir. 33. 



F. senilis. Sowerby, III. p. 105, pi. 258. 



Oblii|Uoly heart-shaped, convex ; hinge very strong ; sur- 

 face with from sixteen to eighteen strong, sub-imbricated 

 ribs ; lunette obsolete ; substance of tho shell thick ; internal 

 margin crenulated. 



The Red Crag, Sutton, and the Coral Crag, Ramshot. 



10. Venericardia tenuicosta. — The Thin-Ribbed Vene- 

 ricardia, pi. LXXXIII. fig. 25. 



V. tenuicosta. Geo. Trans. 2d Ser. IV. p. 335, pi. 11, 

 fig- 7*. 



Nearly orbicular, or slightly quadrangular; convex, and 

 somewhat heart-shaped ; surface with numerous fine longitu- 

 dinal ribs, crossed by strong strias, which make the ribs feel 

 rough to the touch ; lunette oblong, rather hollow ; posterior 

 side slightly even ; internal margin crenulated. 



Tho Gault, Folkstone, and Vale of Wardour. 



Genus XX VIII.— PULLASTRA.—.%«'«%. 



Shell equivalve, inequilateral, the anterior side being the 

 shorter ; three cardinal teeth in each valve, situate near to 

 each other, and generally within a notched or cleft termina- 

 tion ; and in a few species the central tooth is deeply so ; two 

 lateral, somewhat rounded, muscular impressions ; pallial im- 

 pressions with a large sinus ; ligament external, and partly 

 concealed by the dorsal margins of the valves. 



1. Pullastra l^vis. — Smooth Pullastra, pi. LXXXIII. 

 fig.7- 



P. Icevis. Sowerby, Silur. Syst. pt. II. p. 602, pi. a, 

 tig. la. 



Shell transversely elongated, a little convex, smooth, plain ; 

 beaks very small ; anterior side short ; posterior side large, 

 somewhat flattened or sub-truncated, and nearly parallel with 

 the hinge-line ; length three quarters of an inch ; breadth one 

 inch and a quarter. 



In the lowest beds of the Old Red Sandstone, at Horeb 

 Chapel, Wales. 



2. PrLLASTRA COMPLANATA. — Tho Suiooth Pullastra, pi. 

 LXXXIII. fig. 8. 



P. complanata. Sowerby, Silur. Syst. pt. II. p. 609, pi. 5, 

 fig. 7. 



Shell transversely elongated, its width being double its 

 length, compressed, smooth ; anterior side short and rounded ; 

 posterior side long and sub-acute, with an oblique edge'; 

 beaks obtuse, and placed near the anterior side ; length three 

 quarters of an inch ; breadth an inch an a half. 



The Upper Ludlow Rock, Barley Brook, Linley, near 

 Bridgenorth. 



3. Pullastra perigrina. — Tho Marsh Pullastra, pi. 

 LXXXVIII. figs. 1, 2. 



Unio peregrinus. Phillips, Geo. York, I. p. 115, pi. 7, 

 fig. 12. 



Ovate ; beaks rather obtuse, and somewhat remote ; hinge- 

 line oblique ; anterior side short ; posterior side long ; both 

 extremities rounded ; basal line gently arcuated ; back gra- 

 dually sloping downwards; surface smooth, with a few well- 

 marked concentric furrows. 



