Spirifer. 



MOLLUSCA. 



113 



60. Spirifeb elongata The Elongated Spirifer, pi. 



LII. fig. 3. 



Spirifera elongata. Phillips, II. p. 220, pi. II, fig. 9. 



Elongated, somewhat pentaedral, sides nearly flat, smooth ; 

 with numerous, rather broad, depressed, longitudinal radiations; 

 a shallow mesial furrow ; base flat, and straight. 



Mountain Limestone, BoUand. 



Section VI Filos.e Surface with prominent, radi- 

 ating, thread-like striae. 



61. Spirifer resupinata. — The Resupient Spirifer, pi. 

 LII. fig. 6. 



Spirifera resupinata. Phillips, II. p. 220, pi. 11, fig. 1. 



Transversely elliptical ; umbones small, approximate ; upper 

 valve depressed in the middle ; lower valve concave, and undu- 

 lating; surface covered with numerous, fine, longitudinal, diver- 

 gent strife, which at intervals rise into prominent spinous lines. 



Mountain Limestone, Dowall, near Bu.tton, Derbyshire ; 

 BoUand, Greenhow Hill, Hawes, and Otterburn. 



62. Spirifer radialis The Radiating Spirifer, pi. LII. 



fig. 8. 



Spirifera radialis. Phillips, II. p. 220, pi. 11, fig. 5. 



Semielliptical, greatly elongated transversely, its width being 

 upwards of tliree times its length; hinge line nearly parallel; 

 base semicircular; whole surface covered with strong, divergent 

 ribs, with intervening smaller ones, crossed by imbricated 

 lamellaE! ; umbones obtuse. 



Mountain Limestone, Cumberland and Florence Court. 



63. Spirifer glabistria The Smooth-striated Spirifer, 



pi. LII. fig. 7. 



Spirifera glabistria. Phillips, II. p. 220, pi. 10, fig. 19. 



Transversely oblong ; umbones obtuse, approximating; sur- 

 face with fine, longitudinal, radiating striae ; mesial fold pro- 

 duced. 



The Mountain Limestone, BoUand. 



SUPPLEMENTARY SECTION. 



64. Spirifer iieteroclitus. — The Heterocitical Spirifer, 

 pi. LII.* fig. 17, 18, 19. 



Spirifer helerocliticus. PhiUips, Pal. Fos. p. 72, pi. 29. fig. 

 125. 



Acutely pyramidal, or converging on four faces to the pointed 

 umbo of the lower valve, the widest area of the four being that 

 under the beak ; the smaller valve forming a rounded base to 

 the shell ; foramen very long, narrow, and frequently obtect ; 

 mesial fold broad, and well defined in the larger valve, with 

 four or five lateral, obtuse, radiating plaits, provided with trans- 

 verse stria;; beaks in some specimens arc bent irregularly back- 

 ward or forward. 



Found at Barton, Newton, and South Devon. 



65. Spirifer speciosus The Handsome Spirifer, pi. 



LII.* fig. 24, 25. 



Spirifer speciosus. Schloth, pi. 16, fig. 1. Spirifer costata, 

 Phillips, Pal. Fos. p. 77, pi. 30, fig. 134. Sowerby, Geo. Trans. 

 V. 2nd series, pi. 55, fig. 5, 6. 



Transversely elongated, fusiform, convex, with broad, pro- 

 minent, divergent ribs, five or six on each side of the umbones, 

 where there are two approximate and more elevated than the 

 others ; lower valve with a deep and broad depression, circum- 

 scribed by two strong ribs ; cardinal area broad, with parallel 

 margins. Length hardly a sixth of its width. 



In soft Slate-stone at Fowey, and in hard Blue Slate at Looe 

 and Tintagel, also at Hope, Ogwell, and Berry. 



66. Spirifer biloba — The Two-lobed Spirifer, pi. LII.* 

 fig. 20, 21, 22. 



Terehratula sinuata. Sowerby, Linn. Trans. XII. p. 516, 

 pi. 28, fig. 5, 6. Spirifer sinuatus, Sowerby, Sil. Syst. p. 630, 

 pi. 13, fig. 10. 



Obcordate, deeply bilobate, eared, and longitudinally striated; 

 larger valve more convex than the smaller, with an incurved 

 beak ; hinge area triangular. Length and breadth three lines 

 and a half. 



Found in the Wenlock Shale at Hay Head and Malvern. 



67. Spirifer giganteus The Gigantic Spirifer, pi. LII.* 



fig. 23. 



Spirifer giganteus. Sowerby, Geo. Trans. V. 2nd series, pi. 

 55, fig. 1, 2, 3, 4. Phillips, Pal. Fos. p. 219, pi. 30, fig. 130. 



Convex, sides cuspidate, and with numerous, divergent, radi- 

 ating ribs, emanating from the umbones, nine or ten of which 

 are more prominent in front, which is deeply emarginated; with 

 somewhat conspicuous, concentric lines of growth crossing the 

 ribs. Frequently attaining nine inches in width. 



Found at Tintagel and Petherwin. 



68. Spirifer stbiatulus. — The Striated Spirifer, pi. LII.* 

 fig. 26. 



Alrypa polygramma. Sowerby, Sil. Syst. p. 637, pi. 21, fig. 

 4 a. Terehratula striatula, Schloth, pi. 15, fig. 4. 



Transversely obovate ; valves unequally convex, the lower 

 one vfith a wide, shallow, longitudinal canal along the middle; 

 sides with numerous, fine, radiating strise, increasing as they 

 approach the sides and base of the valves. Length and breadth 

 about an inch. 



Found in the Lower Silurian Rocks at Powis Castle. 



69. Spirifer radiatus The Rayed Spirifer, pi. LII.^ 



fig. 27, and fig. 60, var. 



Spirifer radiatus. Sowerby, Sil. Syst. p. 625, pi. 12, fig. 6. 

 lb. p. 638, pi. 21, fig. 5, var. 



Larger valve with the umbo much produced, and an incur- 

 vected beak ; bingo area subtriangular ; lesser valve with a 

 double produced rib in the centre, and an intermediate furrow; 

 whole surface with numerous, somewhat irregular, divergent 

 stria?. Length fourteen lines ; width sixteen lines ; each valve 

 six lines in depth. 



Sowerby considers this as identical with S. lineatus, pi. L. fig. 6, 7, 

 but its greatly produced beak and general contour at once point it out as 

 separate. Fig. 60 is a variety with straight beaks. 



Found in the Dudley an<! Wenlock Limestone at Abbcrlcy 

 Lodge, Dudley, Wenlock, and Tyncwidd, Cacrmarlhenshire. 



70. Spirifer phal^na — The Moth-like Spirifer, pi. LII.* 



fig. 28. 



Spirifera phalana. Phillips, Pal. Fos. p. 7 1 , pi. 28, fig. 1 23. 



Transversely elongated, the sides rounded ; larger valve with 

 a deep, broad, mesial furrow ; surface with regular, equidistant, 

 small ridges, and shallow intermediate furrows ; beak produced. 

 2 f 



