Catillus. 



CONCH IF ERA. 



165 



I 



times its length ; ilepressed, slightly curvoil, ami smooth ; ante- 

 rior extremity truncated, open ; teeth of the hinge variously 

 ilisposei', irregular, ami linear, those of the exterior extremity 

 are most proJaced, an<l placed perpendicular to the hinge- 

 line ; the others lie in the same direction with it, and are fre- 

 quently curved, with ahuut four depressions. 



The Lower Greensand, Sussex ; Isle of Wight ; Dorset and 

 Devonshires. 



2. Gervillia acuta ? — The Acute Gervillia, pi. LXIX. f .5. 

 G. acuta. Sowerby, VI. p. 15, pi. 510, fig. 5. 



Ovate and lanceolate, its width four times its length ; ob- 

 lique, narrow, somewhat depressed, and a little curved ; sub- 

 stance of the shell very thin ; anterior portion greatly attenu- 

 ated, the opposite extremity rounded ; teeth of the bingo 

 variously disposed. 



In the Great Oolite, Collyweston. 



3. Gervillia avictloides. — The Birds-Wing Gervillia, 

 pi. LXIX. figs. 7, 8, 9. 



G. amculoides. Sowerby, VI. p. 16, pi. 511. Perna am- 

 culoiiks. lb. I. p. ] i", pi. Ci3. 



Obliquely ovate, and lance-shaped, somewhat curved, with 

 both extremities acute ; hinge-line occupying nearly half the 

 length of the shell ; teeth few, all similarly disposed. 



Greensand, Blaekdown and Lyme Regis ; Lower Green- 

 sand, Sandgate ; the Portland Sand, Langcombe ; and the 

 Oxford Clay, Osraington and Upware. 



4. Gervillia lanceolata. — The Lance-shaped Gervillia, 

 pi. LXIX. fig. 4. 



G. lanceolata. Goldfuss, p. 123, pi. 115, fig. 9. G. acuta. 

 Phillips, Geo. York, I. pi. 9, fig. 30. 



Much elongated transversely, ita breadth being five limes its 

 length ; the hinge-line long, nearly half the width of the shell, 

 nearly strai^'ht and oblique, tapering to a point, the opposite 

 side a little narrowed from the hinge, with a rounded, blunt 

 termination ; surface nearly smooth, with a few nearly regu- 

 lar, faint lines of growth. 



The Great Oolite, Collyweston, Brandsby, and Cloughton. 



5. Gervillia ixconspicita. — Tiie Inconspicuous Gervillia. 

 G. inconitpkua. Phillips, Geo. York,II. p. 212, pi. LXI.** 



fig. 30. 



Transversely elongated ; hinge-linge extending the whole 

 length of the valve ; anterior side short, rounded ; posterior 

 sije truncated ; surface with concentric wrinkhs. 



Carboniferous Limestone, Castleton, Derbyshire. 



G. Gervillia lamino.sa. — The Laminated Gervillia, pi. 

 LXVII. figs. 10, 16. 



G. Inminosa. Phillips, Geo. York, II. p. 212, pi. 6, fig. 10. 



Very oblique infiated hinge-line, extending the whole length 

 of the shell, with auriform processes on both sides of the beaks, 

 the anterior one short and blunt ; the posterior lengthened and 

 acute; surface smooth, with concentric lines of growth ; base 

 rounded. 



Fig. 16 is a cast of the inside. 



The Carboniferous Limestone, Bolland, Colstcrdale. 



7. Gervillia .minor.— The Small Gervillia,pl. LXP* f.31. 



G. minur. Brown, Trans. Manchester Geo. Soc. I. p 227, 

 pi. 7, fig. 70. 



Very oblique ; umboncs flat, placed much to one side ; 

 hinge-line long, straight ; surface with numerous concentric, 



strong, rude wrinkles, with lesser intermediate ones. Length 

 three-eighths of an inch, breadth throe-fourths of an inch. 



Carboniferous Limestone Shiile, High-Green Wood, Vale 

 of Todmorden. 



8. Gervillia squamosa. — The Scaly Gervillia, pi. LXVII. 

 fig. 18. 



G. squamosa. Phillips, Geo. York, II. p. 212, pi. G, fig. 9- 



Greatly oblii)ue ; hinge-line nearly straight ; one ear large, 

 the other small ; posterior side ridged ; surface with scaly 

 stria;. 



The Carboniferous Limestone, Bolland. 



9. Gervillia lata. — The Broad Gervillia, pi. LXIX. 

 figs. 1, 2. 



G. lata. Phillips Geo. York, I. pi. 1 1, fig. 16. 



Obliquely transverse, much inflated, hinge-line long, oblique, 

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

 surface smooth, with many equidistant concentric lines of 

 growth. 



The Inferior Oolite and Blue Wick, Glaize Dale. 



Genus XXVIII.— CRENATULA.—tamarci-. 



Shell sub-equivalve, compressed, inequilateral, oblique: 

 somewhat distorted and lamellar; hinge-line lateral, linear, 

 nearly straight, marginal, and internally crenulated ; the cre- 

 nulffi formed in a continuous series along the hinge, each of 

 them presenting a small rounded callosity, and excavated for 

 the reception of part of the cartilage, the intervening ridges 

 covered with a true ligament ; muscular impressions almost 

 obsolete, of an oblong form, and situate near the anterior mar- 

 gin of the pearlaceous substance. 



1. Crenatula vkntrtcosa.— The Bellied Crenatula, pi. 

 LXI.-"- fig. 4. 



C. ventricosa. Sowerby, V. p. C4, pi. 443. 



Ovate, elongated, gibbose, ventricose, and carinated ; 

 hinge-line short, posterior side much comjiressed, with its 

 edges a little produced, but not lobate ; front and anterior 

 side rounded ; inside pearlaceous. 



In the Lias, Bosworth, Leicestershire, Yorkshire, and Vale 

 of Gloucester. 



2. Crenatdla Listeri. — Lister's Crenatula, pi. LXL* ■ '^ 

 fig. 5. 



C. Listeri. Parkinson, Org. Rem. III. p. 220, pi. 15, f. o- 

 Elongated ; hinge-line oblique ; crenulations large ; valves 

 narrow above and wide below. 

 The (rreat Oolite, Shotover. 



3. Crenatula producta.— The Produced Crenatula, pi- 

 LXI.*** fig. G. 



V. producta. Parkinson, Org. Rem. III. p. 221, pi. U. 

 figs. C, 7. 



Much elongated ; hinge-line considerably oblique, with tour 

 large crenulations ; beaks rather prominent, and a little turned 

 to one side ; basal margins of the valves much produced, and 

 extending considerably below the body of the shell ; external 

 surface with concentric laminae. 



Tlie Oolite, Shefford, Bedfordshire. 



Ge.nusXXIX.— CATILLUS.— iBronynwrt. 

 Shell thick, inequivalve, inequilateral ; triangular, deep, 



