MOLLUSCA. 



TUHRILITES. 



Sowerby, Min. Conch. I. p. IG9, pi- 74. Maiitell, Geology 

 of Sussex, p. 124. pi. 24. fifp. 2, 3, G. 7. D.-. Gfology S.IC. 

 of KuglaiiJ, p. 15I», tig. 1. Uronii in Pupiilur CyciopuKlia, 

 pi. 66, fig. 2. Turrililes costutala, Lamarck. An. San V»rt, 

 Vll. p. 64(J. 



1 IiU>ro.itropli<- ; llif centre of the volutions provided witii 

 a single nnv of large tiibi-rcles from fifteen to sixteen in 

 numhiT, being ntarly eipiidistant to their diameter, and those 

 on the body elongated, forming irregular tubrrcular costa;, 

 which are reflected towards the aperture, with three bands of 

 »mall ones at their ba.se ; volutions much inflated and deeply 

 divided by an undulating suture, with tlii'ir inferior surface 

 provided with radiating ribs, that terminate in the lowermost 

 row of tul>ercles ; siphunclc situate inttrniediately between 

 the larger tubercles and the upper edge of the volutions, 

 which is impressed by the ribs of the preceding volution ; 

 l>asc of the aperture contracted. 



l"ig. 7. pi. IV. is a persj)ective representation of a cast of 

 T. luberculatus in an inverted position, to exhibit the radiated 

 rilii on the base of the volutions. 



This gigantic shell was discovered by G. \. Mantell, Esq. 

 in the Marie stratum at Midillehani, on the estate of the Kev. 

 J. t'on-itable, parish of Kingmer, Sussex, about two feet under 

 the surface, while they generally occur at a depth of six or 

 eight feet. It measuri-s five inches at the base, and is sup- 

 posed to have been upwards of tw o feet when i)erfect. 



This magnificent Hritish specimen, says Mantell, " is a 

 mst of indurated niarlc of an ochraceous colour, retaining in 

 one part a thin iridescent pellicle of the pearly coat of the 

 shell. Six volutions remain, the largest of which is five 

 inches and a half in diameter. Upon a moderate calculation, 

 the original, when perfect, must have exceeded two feet in 

 length." 



M. Denis Montfort mentions a specimen found in the 

 mountain of St Catharine, near Rouen in Normandy, which 

 measured eighteen inches in length. This fossil " appears to 

 have been in such a state of perfection, as to allow of its form 

 being made out completely. It is regularly formed into a 

 spire, the whorls of w hicli are projecting and articulated, the 

 foliaceous sutures produced by the edge of the septa being 

 ap|)arent. The opening of the shell is nearly round ; the 

 columella flat, without any folds ; and the septa perforated 

 nearly in the centre by a syphon." 



2. T. usDULATA. — The Waved Turrilite, IV. fig. 1, and 

 )il. III. figs. 4 and <(. 



Mantell, Geology of Sussex, p. 121, pi. 23, figs. 14 and 

 16, and pi. 24, fig. 8. Sowerby, Min. Conch. I. p. 171, pi. 75, 

 figs. 1 , 2, 3. Mantell, Geology S.K. of England, p. 1 59, fig. 2. 



Volutions heterostroj)he, with numerous, prominent, e(|ui- 

 distanl, gently undulating, oblique, longitudinal ribs, gene- 

 rally covering the whole volution ; those on the body usually 

 more contiguous, and running into each other. 



This species is frequently three inches in diameter. First 

 noticed and descrlbe<l by G. ,\. Mantell, Esq., and is charac- 

 terized by its produced, longitudinal series of ribs, which 

 reach from one suture of the spire to another, but are undu- 

 lated in some examples. In a number of s]iecimens the ribs 

 arc oblii|ue, and somewhat tubercular, which has led some 

 Naturalists to consider them identical with the Turrilitcs 

 cottalut. In casts of the adult shell, the characters of the 

 «|)ccie» are, however, distinctly marked, ond leave no doubt 

 of the propriety of their separation.'' 



In Eigs. 4 and 9, pi. III. the ribs are singularly depressed, 

 and with little separation between them. 



Found at Hamsey Marie pit, Sussex. 



There is a variety of Ttirrilitts imdulatus with the ribs 

 somewhat concave, su])posed to bi- a large shell. 



;{. T. cosTATA. — The Kibbed Turrilite, pi. Ill fig. 6. 



l)e Montfort, Journal de Physic, an. 7, p. 1, pi- 1. fig- !• 

 Sowerby, Min. Coiieh, 1. p. 81, pi. 30. Parkinson's Organic 

 Uemains, III. p. 147. .Mantell, Geology of Sussex, p. 133, 

 pi. 23, fig. 15, and pi. 24, figs. 1, 4, G. 



Ileterostrophe, upper half of the volutions provided with 

 about twenty smooth, rounded, widely set, prominent, equi- 

 distant, subulate ribs, which reach to the centre of the volu- 

 tions ; w ilh a zone of prominent, slightly elliptical tubercles 

 beneath, towards the infvrlor margins of the volutions; the 

 latter nearly obscured by the next volution ; those on the 

 body bi-ing all distinctly visible. In many instances the 

 tubercles and ribs pass into each other. This species varies 

 frotn three to six inches in length. The casts of the Inside 

 are compressed into a somewhat oval form. 



First discovered at Hamsey Marie pit, Sussex, and at 

 Clayton, by (J. A. Muntell, Esq., and has since been found In 

 the Green sand at llornlngsliam, Wiltshire. The Sussex 

 specimens very rarely exceed three or four volutions, and are 

 invariably in some degree compressed ; they vary from one 

 to seven inches in circumference, and I'rom three to five inches 

 in length ; the body is but rarely preserved, and no remains 

 of the shell are discoverable. 



4. T. oBLiuu.\. — The Oblique Turrilite, jil. III. fig. 6. 



Sowerby. Min. Conch. I. p. 172, ])1. 75, 



fig. 4. 



Volutions dextral, very deeply divided, the upper ])ortions 

 being narrow and abruptly w Idening towards their base, and 

 when taken individually resemble a truncated cone, the base 

 of each furnished with a zone of oblique, elliptical tubercles, 

 giving the volutions an angular appearance ; suture line veil 

 marked. 



Fragments only of this species have been obtained. First 

 found in the Micaceous sandstone near Devizes by Mrs Gent. 



5. T. Beiigeri — Herger's Turrilite, pi. III. fig. 8. 



liucklaiid's Uridgewaler Treatise, II. p. (J.""), pi. 44, fig. 14. 



Volutions of the spire turretcd, dee))ly divided, and 

 flattened above ; each provided with longitudinal oblong 

 ovate, continuous rows of tubercles, in the form of ribs, pre- 

 senting a somewhat catinated appearance ; the upper volu- 

 tion with three, and the next with five series : siphunclc 

 apparent near the upper or dorsal mai'gin of two volutions 

 at a a ; the sinuous edges of the transverse plates are visible 

 in the central volution, and the entire surface of a transverse 

 plate is laid open on the smaller end of the third volution, 

 she-wing its lobes and saddles to be analogous to the same 

 parts in Ammonites. 



I'ound in the (Jrccn sand. 



A charaett ristic specimen of this species, so interesting to 

 Genlogleul inquirers, is in the cabinet of that excellent Geo- 

 logist, (i. U. (jrecnough, Esq. of London. We have intro- 

 duced it to exhibit its peculiarity of structure. 



The Turrililes <lo not appear until the commencement of 

 cretaceous formations. 



-Mr .Mantell says, " there are jjrohably no localities In Eng- 

 land so rich in the various species of Turrilitcs as the Marie 

 pits in the vicinity of Lewes." .\nd we may add, they are 

 likewise rich in many other species. 



