Pleurotoma. 



MOLLUSCA. 



65 



which are most prominent near the middle of the volutions ; 

 aperture oblong-ovate, about two-fifths the length of the shell, 

 terminating in a short, slightly curved canal. 



Found in the London Clay at Stubliington. 



4. P. ACUMINATA The Acuminated Pleurotoma, pi. 



XXXVII. fig. 6. 



Pleurotoma acuminata. Sowerby, Min. Conch. II. p. 105, 

 pi. 146, fig. 4. Fleming, Brit. An. p. 355. 



Fusiform ; body a little longer thsii the spire ; base attenu- 

 ated ; spire consisting of nine greatly produced volutions, a 

 little flattened above, deeply separated by the suture, and each 

 provided with a series of projecting, blunted, wide-set tuber- 

 cles ; body with five or six longitudinal, undulating costae, 

 crossed by numerous, transverse, sharp, subtuberculated, nar- 

 row, undulous ribs,' with many intermediate and fine striae; 

 aperture elongated, narrow, which with the beak is about equal 



Shell greatly elongated ; body considerably shorter than the *° ''^'^ ''^° ''"'''"° 'ength of the shell ; beak tapering gradually 



spire, which consists of nine or ten (urroted, inflated volutions, ^''°'" '•''° "PP®"" POf^'O" "^ the body ; the longitudinal, irregular 



which are concave above, provided with a fimbriated margin, ''"®^ °^ growth make the shell feel rough to the touch. Dia- 



and terminating in an acute apex, the volutions being separated '"°''^'" °^ ^^° ^'^'^" ^''""^ one-fourth its length, 

 by an elevated thread-like suture; the whole shell with many Found in the London Clay at Stubbington. 



longitudinal, slightly waved ribs, which are thickest and more 

 elevated above, on the body, and sulcato-striated below; many 

 spiral, fine striae invest the shell from the apex to the base ; 

 aperture oblong-ovate, which, including the beak, is one-fifth 

 the length of the shell, and ending in a wide canal. 

 Found in the London Clay at Highgale Hill. 



5. P. EXOKTA 



fisr. 2. 



8. P. BREviROSTRA — The Short-beaked Pleurotoma, pi. 

 XXXVn. fig. 3, 4. 



Pleurotoma hreinrostrum. Sowerby, Min. Conch. IV. p. 

 120, pi. 387, fig. 2. Fleming, Brit. An. p. 355. 



Elongated, turreted ; body short ; spire long, consisting of 



ten or eleven ventricose, abruptly tapering volutions, flattened 



The Risen Pleurotoma, pi. XXXVII. at top, separated by a deep suture, and terminating in an acute 



apox ; lower parts of volutions of the spire, and upper portion 



Pleurotoma cxorta. Sowerby, Min. Conch. II. p. 104, pi. of the body, with many elevated, longitudinal ribs; whole shell 



146, fig. 2. Fleming, Brit. An. p. 354. Murex exortus, 

 Grander, Foss. Hant. p. 20, pi. 2, fig. 32. 



Elongated, turreted ; base conical ; spire and body of nearly 

 equal length ; spire consisting of nine or ten inflated volutions, 

 which are concave and smooth above, convex below, with twelve 

 or fourteen longitudinal, undulated costae, which are most pro- 

 minent on the spire ; the smooth and concave portion of the 

 volutions is bounded by the abrupt commencement of the ribs, 

 with many tuberculated, spiral linos; length of aperture and 

 beak equal to two-fifths of the length of the shell, and elon- 

 gated in form, ending in a slightly curved, short canal ; outer 

 lip thin ; inner lip slightly reflected on the columella. 



Found in the London Clay at Barton Cliff. 



6. P. 



crossed by numerous spiral stria;, which are strongest upon the 

 middle of each volution ; aperture obovatc, ending in a short, 

 slightly curved narrow canal; outer lip thin; inner lip smooth, 

 broadly reflected on the columella. 



Found in the London Clay at Muddiford. 



9. P. FUSiFOUMis — The Spindle-shaped Pleurotoma, pi. 

 XXXVIL fig. 14. 



Pleurotoma fusiformis. Sowerby, Min. Conch. IV. p. 119, 

 pi. 387, fig. 1. Fleming, Brit. An. p. 355. 



Elongated, fusiform; body long; spire short, consisting of 

 seven abruptly tapering volutions, slightly flattened above, and 

 subcarinated, separated by a striated, and elevated smoothish 

 fillet, their lower portions furnished with eight or nine longitu- 



ROSTBATA. — The Beaked Pleurotoma, pi. XXX VII. dinal, somewhat obscure, depressed ribs; whole shell with deep 



fig. 11. 



Pleurotoma rostrata. Sowerby, Min. Conch. II. p. 104, pi. 

 146, fig. 3. Fleming, Brit. An. p. 354. Murex rostratus, 

 Brander, Foss. Hant. p. 21, pi. 2, fig. 34. 



Shell fusiform ; body and spire of nearly equal length ; spire 



sj)iral stria;, and also with longitudinal stria;, which is arcuated 

 near the top of the volutions, and following the sinus in the 

 upper part of the outer lip ; aperture oblong, lanceolate, widest 

 above, and narrowing as it descends, terminating in a widish 

 canal; beak not well defined; outer lip rather thick; inner lip 



consisting of eight or nine expanded, convex volutions, slightly reflected on the columella, and transversely striated. Thi 



concave above, somewhat ventricose and rough below, and 

 separated by a wide suture, granulated in the centre; upper 

 part of the body, and ventricose portion of the volutions of the 

 spire, provided with short, broad, rather obscure, longitudinal 

 ribs ; the whole shell crossed by numerous spiral ridges, and 

 narrow, elevated, sharp, somewhat undulating ribs, which feel 

 rough to the touch by means of the lines of growth ; the whole 

 surface obscurely decussated, but more distinct towards the edge ; 

 aperture ovate, ending in a long, narrow, and nearly straight 

 canal. 



Found in the London Clay at Barton Clilf, Hampshire, and 

 at Devizes. 



7. P. ATTENUATA — The Slender Pleurotoma, pi. XXXVIL 

 fig. 1. 



Pleurotoma altenuutu. Sowerby, Min. Conch. II. p. 103, 

 pi. 146, fig. 1. Fleming, Brit. An. p. 351. 



shell feels rough to the touch, from (he elevated lines of growth 

 and decussating striae. 



Found in the London Clay at Highgato Iliii. 



10. P. piuscus — The Ancient Pleurotoma, pi. XXXVIL 

 fig. 12, 1.3. 



Pleurotoma priscus. Sowerby, Min. Conch. IV. p. 1 19, pi. 

 386. Fleming, Brit. An. p. 355. Pleurotoma clavicularis, 

 Lamarck, Env. de Paris, p. 69. Hist. Nat. An. San. Vert. 

 VII. p. 98. Murex priscus, Brander, Foss. Hant. p. 16, pi. 1, 

 fig. 25, and pi. 3, fig. 44. 



Fusiform, turreted, smooth ; base of body transversely sul- 

 catcd ; body and spire of about equal length ; spire consisting 

 of eight slightly convex volutions, terminating in a sharp apex ; 

 the volutions separated by a flat suture, on which are two or 

 three wide spiral stria;; base of shell considerably produced, but 

 destitute of a distinct beak, blunt at the lower extremity, and 



R 



