220 



CONCHIFEIIA. 



Si'lIEN 



nearly straight ; surface with concentric furrows, which be- 

 come suddenly angular as they pass over the ridge and proceed 

 to the hinge-line. 



The Carboniferous Limestone, Fermanagh, Ireland, and 

 Loweek. 



14. SanguInolaria parvula. — The Small Sanguinolaria, 

 pi. XC. fig. 38. 



S. parvula. Bean, Mag. Nat. Hist. N. S. III. p. 59, f. IS. 



Transversely oblong oval, compressed, smooth, with a few re- 

 mote lines of growth ; anterior side somewhat rounded ; poste- 

 riorly more acute and sub-truncated ; beaks nearly central, and 

 very obtuse ; length, a quarter of an inch ; breadth, half an inch. 



The Cornbrash, Scarborough, Yorkshire. 



15. Sanguinolaria elegans. — The Elegant Sanguinolaria, 

 pi. XC. fig. 28. 



S. elegans. Phillips, Geo. York, I. pi. 1 2, fig. 9. 



Elliptical ; anterior side a little narrowed and rounded ; 

 posterior side obliquely sub-truncated; hinge-line nearly 

 straight ; beaks obtuse ; surface with many regular transverse 

 furrows emanating from the anterior side, and terminating 

 where the diagonal sides pass from the beak to the margin, 

 where it produces an angle. 



The Lias, Upper Shale, Yorkshire. 



16. Sanguinolaria elliptic a. — The Elliptical Sanguino- 

 laria, pi. XC. fig. 18. 



5. eUiptica. Phillips, Pal. Foss. p. 34, pi. 17. fig. 53. 



Nearly elliptical and equilateral ; hinge- line almost straight ; 

 the sides rounded ; beaks obtuse; surface concentrically striated. 



The Devonian Rocks, Combe, near Ashburton, and Yealm 

 Bridge, near Launceston. 



17. Sanguinolaria gibbosa. — The Gibbous Sanguinolaria, 

 pi. XC. fig. 29. 



S. gihhosa. Sowerby, V. p. 92, pi. 548, fig. 3. 



Much elongated transversely ; gibbose, smooth ; sides 

 slightly gaping and roundeil ; beaks obtuse, situated near the 

 anterior side ; surface smooth. 



The Carboniferous Limestone, Ireland. 



18. Sanguinolaria sulcata. — The Furrowed Sanguino- 

 laria, pi. XC. fig. 41. 



S. sulcata. Phillips, II. p. 209, pi. 5, fig. 5. 



Transversely elongated ; anteriorly short and narrowed ; 

 posteriorly lengthened, and somewhat expanded ; beaks obtuse, 

 situate near the anterior side ; hinge-line a little curved and 

 hollow ; surface transversely furrowed, which become broad at 

 the posterior side ; a few obsolete, longitudinal striaj. 



The Carboniferous Limestone, Otterburn and Kendal. 



Tribe II.— LITHOPHAGI. 



Boring shells, destitute of accessory pieces, and more or less 

 gaping at their anterior side ; ligament of the valves external. 



rather triangular ; but some species are transversely elongated, 

 and others sub-quadrate ; posterior side rounded ; anterior 

 side somewhat produced, more or less attenuated, and gene- 

 rally gaping ; each valve provided with two cardinal teeth, 

 which, in some instances, are curved and acute, especially the 

 posterior tooth in the left valve, and the anterior tooth in the 

 right ; the teeth are sometimes grooved internally, and the 

 anterior tooth in one valve is broad and bifid ; and in some 

 instances the teeth are obtuse and short ; two muscular im- 

 pressions in each valve^ that on the posterior side somewhat 

 oblong, and the anterior one sub-orbicular ; p.illial impression 

 with a large sinus ; ligament external, but, in some species, 

 nearly concealed by the prominent anterior margin of the 

 valves near the beaks. 



1. Petricola inflata. — The Inflated Petricola, pi. XC. 

 figs. 1, 2, 3. 



Sub-triangular, gibbose, and somewhat cordiform ; beaks 

 produced and approximate, anteriorly short, rounded below ; 

 posterior side with the hinge-line angular, and obliquely trun- 

 cated at the terminations ; surface smooth, with an obscure 

 ridge on the jiosterior side from the beaks to the margin, and 

 with remote shallow lines of growth. 



Found in the Lias, while cutting for Kirby Tunnel beyond 

 Coventry. 



2. Petricola l.evis. — The Smooth Petricola, pi. XC.f. 0, 7. 



Obovate, sub-compressed ; beaks rather produced and ap- 

 proximate ; anterior side rounded and shortest ; posteriorly 

 lengthened, and a little narrowed ; surface smooth, with re- 

 mote, irregular lines of growth. 



In the Lias, at Barrow. 



3. Petricola laminosa. — The Laminated Petricola, pi. 

 XC. figs. 4, 5. 



P. laminosa. Sowerby, VI. p. 142, pi. 573. 



Ovate, gibbose, anterior side shortest and rounded ; poste- 

 rior side somewhat acuminate ; beaks obtuse and approxi- 

 mate ; one broad cleft tooth in the left valve, and two small 

 ones in the other ; surface with erect, laminated, concentric, 

 narrow ribs. 



Fig. 5 is probably a distinct species. 



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



4. Petricola canaliculata. — The Canaled Petricola. 



P. canaliculata. Sowerby, Geo. Tr. 2d Ser. IV. p. 16, f. 1 1. 



Orbicular, very convex ; beaks nearly central, and approxi- 

 mate ; surface with numerous longitudinal furrows, which are 

 nearly covered over ; internal edge granulated. 



In the Greensand, Blackdown. 



5. Petricola nuciformis. — The Nut-shaped Petricola. 



P. nucifo7-mis. Sowerby, Geo. Tr. 2d Ser. IV. p. 341, pi. 

 16, fig. 10. 



Sub-orbicular, very convex ; beaks nearly central, and 

 quite approximate ; surface longitudinally striated ; the inter- 

 nal edge serrated. 



The Greensand, Blackdown. 



Genus XLVL— PETRICOLA.— Zamarc/t. Genus XLVIL— SPHENIA.— r^rto/i. 



Shell equivalve, inequilateral, transverse, for the most part Shell transverse, inequivalve, inequilateral ; general fonu 



