Cytherea. 



CONCHIFERA. 



257 



1 . Terebbatuia VIRGO. — The Virgin Terebratula, pi. LI V.* 

 figs. 17, 18. 



r. Virgo. Pliillips, Till Fos. p. 01, pi. Sf), fig. 167. 



Ovato-lanceolate ; uniformly convex ; beak prominent, slightly 

 curved ; front margin somewhat contracted, and nearly straight : 

 sui-face with very fmnt longitudinal and transverse striae, which, 

 viewed through a lens, produces a beautifully reticulated ap- 

 pearance. 



This species somewhat resembles T. hastnta, but differs 

 from it in the beak being more prominent, without an angula- 

 tion, and in the curvature being so slight. 



In the Devonian Shales, Barton, South Devon. 



2. Terebratula similis. — The Similar Terebratula, plate 

 LV.* figs. 8, 9. 



Sub-triangular, inflated ; with three indistinct furrows towards 

 the base of the valve. 

 The Carboniferous Limestone, Dovedale, Derbyshire. 



3. Terebratula annularis. — The Ringed Terebratula, pi. 

 LV.* figs. 01, 02. 



Sub-triangular ; hinge line nearly straight, beak short ; a 

 broad, central, longitudinal furrow in the larger valve : whole 

 surface covered with numerous divergent striae. 



The Carboniferous Limestone, Dovedale, Derbyshire. 



1. OsTREA DURiuscuLA. — The Rough Ostrea, pi. LIX. fig. L 

 0. duriuscula. Philhps, Geo. York. I. pi. 4, fig. 1. 

 Ovoid, compressed, with rough imdulating longitudinal folia- 

 tions. 



The Coral Rag, Maltou, Scarborough. 



1. AvicuLA LONGiAXis. — The Lengthened Axis Avicula, pi. 

 LXI.** fig. 1. 



A. hngiaxis. Buckman and Strickland, Geo. Cheltenham, 

 p. 97, pi. 10, fig. 3. 



Valves equal ; hinge line straight ; anterior side much accu- 

 minated ; the posterior very short : surface with fine ti'ausverse 

 striae ; substance of the shell thin. 



The Lias, foot of Battledown Hill, Hewlett's Road, near 

 Cheltenham. 



2. A\acuLA coMPHCATA. — The Complicated Avicula, plate 

 LXI.** fig. 9. 



A. compUcata. Buckman and Strickland, Geo. Chelt. p. 97, 

 pi. 6, fig. 5. 



Hinge line somewhat obhque ; the right beak short, trans- 

 versely ribbed, and a Uttlc acute ; left beak rounded ; valves 

 considerably twisted, and covered with longitudinal nodulous 

 ribs. 



The Oolite, Leckhampton and Crickley HiDs, near Chelten- 

 ham. 



3. A%acuLA LONOLAREA.— The Long-Areaed Avicula, plate 

 LXI.** fig. M. 



Hinge line lengthened and quite straight ; anterior auricle 

 long, broad, and notched; posterior auricle shorter, narrow, 

 and acute : valves moderately inflated ; surface with longitu- 

 dinal, rather wide, furrows, diminishing as they recede from 

 the anterior side ; posterior side destitute of furrows. 



1. Gervilua acuta. — The Modiola-formed Gervillia, plate 

 LXIX. fig 4. 



Gervillia acuta. Phillips, Geo. York. I. pi. 9, fig. 36. 



Lanceolate, hinge line obUque and lengthened, with a rounded 

 tennination ; apical extremity gradually tapering ; base rounded, 

 surface smooth, with nearly obsolete lines of growth. 



The Great Oolite, Cloughton. 



1. LiTHOPHAGUs ANTiQuus. — The Aucicut Lithophagus, pi. 

 LXXIL figs. 44, 45. 



Cylindrical ; beaks blunt, surface smooth, with a few trans- 

 verse striae towards the umbones. 



Found embedded in a silicious mass of Asteria, from the 

 Coral Rag, Malton, Yorkshire. 



1. Venus tenera. — The Tender Venus, pi. LXXXIV. figs. 

 14,15. 



F. Unera. Sowerby, Geo. Tr. 2nd Ser. IV. p. 335, pi. 11, 

 fig. 7. 



Somewhat lenticular; slightly transverse ; beaks acute ; whole 

 surface curved with fine, regular, concentric striae; lunette 

 lanceolate. 



The Gualt, Folkston. 



1. Cytherea caperata. — The Wrinkled Cytherea, plate 

 LXXXIV. fig. 30. 



Yenm caperata. Sowerby IV. p. 31, pi. 518, fig. 1. 



Orbicular, compressed, somewhat lenticulai- ; lunette heart- 

 shaped ; whole surface covered with numerous small, rounded, 

 well defined, concentric ridges ; with pretty wide intervening 

 ribs. 



The Greensand, Blackdown. 



