SPIEIFEII. 



MOLLUSCA. 



Ill 



Oblong-ovate, rather smooth ; cardinal area rather long ; 

 upper valve flattened, with a broad mesial ridge and three 

 lateral ridges on each side. 



Mountain Limestone, Bolland. 



35. Spirifer duplicicosta. — The Double-ribbed Spirifer, 

 pi. LI. fig. 13. 



Spirifera duplicicosta. Phillips, IL p. 218, pi. 10, fig. 1. 



Transversely elongated; umbones pointed; cardinal area 

 pretty wide; mesial fold angular; surface with numerous, lon- 

 gitudinal, divergent ribs, which become duplicate towards the 

 basal margin ; sides of the shell rounded. 



Mountain Limestone, Derbyshire, Bolland, and Northum- 

 berland. 



36. Spirifer Gloveri. — Glover's Spirifer, pi. LL fig. 

 11, 12. 



Spirifer Gloveri. Brown, Trans. Manchester Geo. Soc. I. 

 p. 224, pi. 7, fig. 60, 61. 



Nearly circular, very convex, with rounded sides ; both valves 

 with a mesial furrow, which widen as they retire from the um- 

 bones, deep in the upper valve, shallow and more effuse in the 

 lower one ; beaks produced, rounded, and rather approximate ; 

 both valves with longitudinal, divergent striae, crossed by dis- 

 tinct lines of growth ; lower margins of valves flexuous, the 

 central base of the upper one terminating in a considerably 

 produced, beak-like process, and hollow in the opposite valve ; 

 hinge line rather short. 



I<ower Sear Limestone Gravel at Sheden Clough, near Cle- 

 viger. 



37. Spirifer filaria. — The Threaded Spirifer, pi. LI. 

 fig. 30, 31. 



Spirifer Jilaria. Brown, Trans. Manchester Geo. Soc. I. p. 

 224, pi. 7, fig. 62, 63. 



Nearly orbicular, rather flat ; beaks small, pointed, and con- 

 tiguous, but not inflected ; exterior surface covered with fine, 

 divergent, longitudinal striae, crossed by numerous lines of 

 growth ; inside of valves with fine, divergent striae ; hinge fine 

 very short. 



Mountain Limestone near Settle, Yorkshire. 



38. Spirifer radiatus. — The Rayed Spirifer, pi. LII.* 

 fig. 6. 



Spirifer radiatus. Murchison, p. 624, pi. 12, fig. 6. 



Cardinal area wide; beaks produced, incurved, and pointed; 

 mesial fold with a hollow, longitudinal groove, producing a 

 doubly pointed base ; whole surface with numerous, regular, 

 radiating strias. 



Wenlock and Dudley Limestone at Wenlock, Dudley ; Ab- 

 berley Lodge and Tynewidd, Caermarthenshire. 



39. Spirifer ptychoides. — The Bent Spirifer, pi. LII.* 

 fig. 7, 8. 



Spirifer ptychoides. Murchison, p. 603, pi. 3, fig. 13. Del- 

 thyris Dalm. Act. Holm. 1827, p. 124, pi. 3, fig. 5. Hising. 

 Pet. Succ. p. 73, pi. 21, fig. 8. 



Somewhat elongated, smooth ; mesial fold longitudinally fur- 

 rowed, with two rounded plaits on each side ; umbo of the 

 larger valve produced, and incurved. Length three lines and a 

 half; width nearly the same. 



Lowest beds of Old Red Sandstone at Fehndre, and also in 

 the Upper Ludlow Rocks at Abberley. 



40. Spirifer crispus? — The Curled Spirifer, pi. LIT.* 

 fig- 9. 



Spirifer crispus. Murchison, p. 610 and 624, pi. 12, fig. 8. 

 Delthjris crispa, Dalm. 1. c. p. 122, pi. 3, fig. 6. Hist. Pet. 

 Succ. p. 73, pi. 21, fig. 5. 



Transversely elongated, gibbose; surface with five or six lon- 

 gitudinal plaits, crossed by elevated laminae; cardinal area wide, 

 obtuse at the sides; umbones remote, with incurved beaks. 

 Length three lines and a half; width five lines and a half: 

 sometimes found larger. 



Dudley Limestone, Walsall; and Wenlock Limestone at 

 Abberley. 



41. Spirifer trapezoidalis — The Trapeziform Spirifer, 

 pi. LII.* fig. 10, 11. 



Spirifer trapezoidalis. Murchison, p. 610, pi. 5, fig. 14. 

 Cyrtia trapezoidalis, Dalm. Act. Holm. 1827, p. 119, pi. 3, fig. 

 2. Hist. Pet. Succ. p. 72, pi. 21, fig. 1. Von Buch, pi. 1, fig. 

 15, 16. 



Almost semicircular, transversely elongated ; cardinal area 

 large and arcuated, the foramen narrow, somewhat shorter than 

 the diameter of the shell, with rounded extremities ; a mesial, 

 elevated rib extends from the beak to the base in the upper 

 valve, with a corresponding furrow in the lower one. 



Upper Ludlow Rock at Usk, Craig-y-garcyd, and Cornbrook- 

 dale. 



42. Spirifer interlineatus The Interlined Spirifer, 



pi. LII.* fig. 12, 13. 



Spirifer interlineatus. Murchison, p. 614, pi. 6, fig. 6. 



Transversely oval, convex ; cardinal area wide ; umbo of the 

 larger valve produced, and its beak so much incurved that it 

 meets the beak of the opposite valve ; rounded at the extre- 

 mities ; with numerous, longitndinal, rounded ribs, five on each 

 side and a more elevated one in the middle, interlined with fine 

 stria. Length five lines and a half; width six lines and a half. 



Amestry Limestone, Amestry ; and also in the Wenlock 

 Limestone. 



43. Spirifer sinuatus. — The Sinuated Spirifer, pi. LII.* 

 fig. 14, 15, 16. 



Spirifer sinuatus. Murchison, p. 630, pi. 13, fig. 10. Tere- 

 bratula sinuata, Sowerby, Linn. Trans. XII. p. 516, pi. 28, fig. 

 5, 6. Delthi/ris cardiospermiforniis, Hist. Anteckn. IV. pi. 7, 

 fig. 6. Dalm. 1. c. p. 124, pi. 3, fig. 7. Hist. Pet. Succ. p. 74, 

 pi. 21, fig. 9. Spirifer cardiospermiformis, Von Buch. Sp. et 



Ort. pi. l,fig. 7. 



Somewhat obtusely heart-shaped, deeply bilobate, and eared; 

 surface with numerous, fine, longitudinal stri* ; larger valve 

 very deep, with an incurved beak; cardinal area triangular. 

 Length and width about three lines and a half. 



Wenlock Shale, Melvern and Hay Head. 



Section IV Glabrat^ — Cardinal area not so wide 



as the shell ; surface for the most part divested of rays. 



44. Spirifer mesoloba. — The Middle-folded Spirifer, pi. 

 LL fig. 18. 



Spirifera mesoloba. Phillips, II. p. 219, pi. 10, fig. 14. 



Suborbicular, compressed, smooth ; umbo of the larger valve 

 produced, beak acute, inflected; cardinal area triangular; mesial 

 fold broad. 



Mountain Limestone, Bolland. 



