70 



MOLLUSCA. 



TCRRITELLA. 



which the base is provided with a deep umbihcus, which is 

 nearly concealed by the reflection of the columellar lip. 

 Found in the Crag at Holywell. 



7. T. ciNGENDA— The Girdled Turrifella, pi. XXXVIII. 



fig. 9. 



Turritella chigenda. Sowerby, Min. Conch. V. p. 160, pi. 

 499, fig- 3. Phillips, Geo. of Yorkshire, I. p. 129, pi- H, %• 

 28. Fleming, Brit. An. p. 304. 



Shell subulate ; body not a third of the total length ; spire 

 consisting of about fourteen volutions, with concave sides, and 

 each with a crenated girdle upon their lower edges; whole shell 

 covered with distinct, but fine, spiral striae, which are closer in 

 the middle of each volution ; the superior volutions of the spire 

 faintly ribbed, but these become obsolete as they descend, until 

 they totally disappear; base flat, with a rounded edge, from 

 which the girdle emanates that winds around the spire. 



Found in the Shale, Robin Hood's Bay, near Scarborough ; 

 and common in the Inferior Oolite. 



8. T. MURICATA The Prickly Turritella, pi. XXXVIII. 



fig. 6. 



Turritella muricata. Sowerby, Min. Conch. V. p. 159, pi- 

 499, fig- 1, 2. Fleming, Brit. An. p. 304. Phillips, Geo. of 

 Yorkshire, I. p. 102, pi. 4, fig. 8. 



Shell subulate ; body more than a third of its length ; spire 

 consisting of ten or eleven rounded, and deeply separated volu- 

 tions, with their upper edges flattened, terminating in an acute 

 apex ; whole surface with strong, rough, muricated spiral striae, 

 the spinous murications being most prominent on the edges of 

 the volutions, and also provided with longitudinal arcuated ribs; 

 base convex, with elevated sharp stria;, but destitute of spines. 

 Length nearly an inch. 



Found in the Coral Rag, and Shale of Robin Hood's Bay, 

 and also at Steeple Ashton ; Seamar, Malton, and Pickering, 

 Yorkshire. 



9. T. ABBREViATA The Shortened Turritella, pi. 



XXXVIII. fig. 13. 



Turritella abbreviata. Sowerby, Min. Conch. VI. p. 125, 

 pi. 565, fig. 2. 



Shell very short, conical, acute; body large, occupying nearly 

 half the length of the shell ; spire consisting of seven volutions, 

 each of their edges defined by a large, obscurely granulated 

 ridge, and two small close-set ones wind round the centre from 

 the base to the apes ; the base produced, and provided with a 

 single ridge. 



Found in the decomposing Mountain Limestone, Bradley, 

 near Newton Bushel, Devonshire. 



10. T. cosTATA.— The Ribbed Turritella, pi. XXXVIII. 

 fig. 24. 



Shell subulate, much elongated, and acute; body short, occu- 

 pying about a fourth of the shell; spire abruptly tapering, 

 consisting of fifteen or sixteen well divided volutions, at the 

 base of each a thread-like, carinated spiral ridge strongly marks 

 the separation of the volutions; whole surface covered with 

 longitudinal costK, which are crossed by numerous fine striae, 

 giving the shell a rough appearance ; base flat, with a carinated 

 margin. 



Found in the Whetstone pits, Blackdown. 



IL T. EXCAVATA The Excavated Turritella, pi. 



XXXVin. fig. 8. 



Turritella excavata. Sowerby, Min. Conch. VI. p. 126, pi. 

 565, fig. 5. Cerithium excavatum, Cuvier and Brongniarte, 

 Env. de Paris, p. 399, pi- 9, fig- 10. 



Shell subulate, short, smooth; body short, occupying about a 

 third of the shell ; spire with eleven or twelve volutions, which 

 are concave in the centre, with prominent edges both above and 

 below ; base convex. 



Full grown shells have their lower volutions with a ridge in the 

 middle. 



Found in the Limestone at Chilmark, Tisbury, Wiltshire. 



12. T. GRANULATA. — The Granulated Turritella, pi. 

 XXXVIII. fig. 18. 



Turritella gramdata. Sowerby, Min. Conch. VI. p. 126, pi. 

 565, fig. 1. Cerithium turritellum, Parkinson, Org. Rem. III. 

 p. 71. 



Shell subulate, tapering acutely ; body occupying more than 

 a third of the length of the shell ; spire consisting of about 

 fourteen slightly inflated volutions, terminating in an acute 

 apex, the upper edges of the volutions with a pretty broad, flat 

 spiral band; whole shell covered viith spiral stria; and numerous 

 nearly regular granules, but with three or four of them some- 

 what larger than the others. 



Found in the Whetstone pits at Blackdown. 



13. T. Tebebra.— The Wimble Turritella, pi. XXXVIII. 

 fig. 27. 



Turritella Terebra. Lamarck, Hist. Nat. VII. p. 56. 

 Sowerby, Min. Conch. VL p. 126, pi. 565, fig. 3. 



Shell turreted, much elongated ; body short, about a third 

 the length of the shell ; spire consisting of thirteen or fourteen 

 ventricose volutions, and terminating in an acute apex ; whole 

 shell covered with numerous, almost equal, spiral sulci. 



This shell is stronger than the recent species of the same name, 

 but differs in no other particular. 



Found in the Suffolk Crag, and has been met with in a clay 

 pit at Tottenhill. 



14. T. Phillipsii Phillips's Turritella, pi. XXXVIII. 



fig. 4. 



Turritella ? Phillips, Geo. of Yorkshire, p. 94, pi. 2, fig. 38. 



Shell subulate, smooth ; body occupying about a fifth of the 

 entire shell ; spire consisting of seven narrow, somewhat ven- 

 tricose and deeply divided volutions, terminating in an acute 

 apex. 



Found in the Speeton Clay at Speeton. 



15. T. QUADRiviTTATA — The Four-banded Turritella, pi. 

 XXXVIIL fig. 16. 



Turritella quadrivittata. Phillips, Geo. of Yorkshire, I. p. 

 129, pi. 11, fig. 23. 



Shell elongated; body occupying nearly half its length; spire 

 consisting of six ventricose, deeply divided volutions, crossed by 

 numerous strong, slightly muricated spiral striae, and terminating 

 in an acute apex ; outer lip thin ; inner lip slightly reflected on 

 the columella. 



Found in the Blue Wick of the Inferior Oolite. 



This shell feels rough to the touch, in consequence of its muri- 

 cated stria;. 



16. T. TENuiSTRiA The Thin-striated Turritella, pi. 



XXXVIIL fig. 11. 



Turritella tenuistria. Phillips, Geo. of Yorkshire, II. p. 

 229, pi- 16, fig. 11. 



