Terebellum. 



MOLLUSCA. 



45 



Genus III. — ANCILLARIA. — La?«arc/e. 



Shell oblonpf, siibcylindrical ; spire short, seldom 

 more than a third of the lengtii of the shell, the suture 

 being' generally obscured by an enamel, which fre- 

 quently covers the whole spire, which is not canaliculate 

 at the sutures ; aperture narrow, effuse above, and 

 notched at the base ; lower portion of the columella 

 smooth, with an oblique, tumid, usually striated varix 

 at the base ; whole outer surface smooth and glossy ; 

 supposed to be devoid of both epidermis and oper- 

 culum. 



1. A. AVEKiFORMis. — The Oat-shaped Ancillaria, pi. 

 XXX. fig. 12. 



Ancillaria aveniformis. Fleming, Brit. An. p. 336. 

 Ancilla aveniformis. Sowerby, Min. Conch. I. p. 225, pi. 

 99, middle right figure. 



Oblong-ovate, elongated, smooth, shining ; spire long ; 

 consisting of four or five volutions, and terminating in a 

 sharp apex ; base two plaited ; inner lip with a sliort exten- 

 sion ; aperture somewhat more than half the length of the 

 shell, slightly contracted, and angular above, and expanded 

 below ; enamel of the pillar lip extended over a third of the 

 volutions in front. 



Found in the London Clay at Barton. 



2. A. Anglic A. — The English Ancillaria, pi. XXX. 

 fig. 15. 



Ancillaria Anglica. Pilkinton, Linn. Trans. VIL p. 116, 

 pi. 11, fig. 1. A. aveniformis, Sowerby, Min. Conch. L 

 p. 225, pi. 99, middle left figure. 



Oblong-ovate, smooth, shining ; spire with four or five 

 volutions, terminating in an acute apex ; aperture somewhat 

 more than half the length of the shell, contracted above, 

 widening in the centre, and expanding at the base ; varix 

 with two plaits ; outer lip slightly inflected, and extending 

 considerablj' below the base of the pillar lip. 



Found at Barton, in the London Clay. 



3. A. TURRiTELLA. — The Turreted Ancillaria, pi. XXX. 

 fig. 13, 14. 



Ancillaria turritella. Fleming, Brit. An. p. 376. Ancilla 

 turritella. Sowerby, Min. Conch. I. p. 226, pi. 99, larger 

 figures. 



Subcylindrical ; spire short, consisting of five subturreted 

 volutions, terminating in an acute apex, and covered with 

 minute, transverse striaa, which are only visible by the aid of 

 a lens ; upper portion of the volutions glossy, the middle 

 parts with minute decussated striae ; varix furnished with a 

 nearly obsolete spiral sulcus, a little above the varix ; colu- 

 mella three plaited, and with a deep sulcus ; aperture exceeding 

 half the length of the shell, acutely contracted above ; outer 

 lip greatly expanded below, and extending somewhat lower 

 than the base of the columella. 



Found at Barton Cliff. 



4. A. suBULATA. — The Awl-shaped Ancillaria, pi. XXX. 

 fig. 20, 21. 



Ancillaria suhulata. Fleming, Brit. An. p. 336. Anacilla 

 subulata. Lamarck, Foss. Env. de Paris, p. 24. Sowerby, 

 Min. Conch. IV. p. 37, pi. 333. 



Shell subulate, elongated, smooth, glossy ; spire lengthened, 

 and abruptly acute, consisting of five volutions ; varix at the 

 base of the columella, finely striated ; aperture not quite 

 half the length of the shell, contracted above and expanded 

 beneath. 



Found in the Upper Marine Formation, Isle of Wight; 

 also near Christchurch, and Hampshire. 



Genus IV.— TEREBELLUM.— iamarc;^. 



Shell convolute, subcylindrical, rolled round its lon- 

 gitudinal axis in the form of an elongated cone, and 

 nearly pointed at the summit ; aperture contracted above 

 and expanded below; base notched; columella smooth ; 

 truncated at the base ; outer lip entire and not thickened. 



1. T. FusiKORME. — The Spindle-formed Terrebellum, 

 pi. XXX. fig. 26, 27. 



Terrebellum fusiforme. Lamarck, Env. de Paris, p. 22. 

 Sowerby, Min. Conch. IIL p. 157, pi. 287- Fleming, Brit. An. 

 p. 330. 



Subfusiform, subcylindrical, tapering somewhat abruptly 

 towards the apex, and gradually towards the base ; spire 

 short, consisting of two volutions and terminating in an obtuse 

 apex ; aperture about three-fifths the length of the shell, with 

 an adpressed straight canal, emanating from its upper angle, 

 and terminating in the apex of the spire ; pillar lip reflected 

 on the columella, which descends considerably lower than the 

 outer lip, which is somewhat inflected and rounded at its base. 

 Found in the London Clay, at Hordwell. 



2. T. coNVOLUTUM. — The Convoluted Terrebellum, 

 pi. XXX. fig. 24, 25. 



Terebellum convolutum. Lamarck, Env. de Paris, p. 21. 

 Seraphs convohitus. Montfort, Conch. S3'st. II. p. 375. 

 Sowerby, Min. Conch. IIL p. 155, pi. 286. Fleming, 

 Brit. An. p. 330. Bulla sopita. lb. Bulla volutata. 

 Brander, Foss. Hant. Collect, fig. 29. a. 



Shell smooth, extremely fragile, subcylindrical, elongated, 

 tapering gradually to both extremities, superior end termi- 

 nating in an obtuse, hollow, pointed apex ; base obliquely 

 truncated ; spire internal, concealed ; aperture longitudinal, 

 extending to the tip of the spire ; columella smooth ; outer 

 lip sharp, and slightly inflected ; diameter about a third of its 

 length. 



Found in the Clay upon the Coast of Hampshire. 



Genus V. — CYPRiEA. — Linnmis. 



Shell ovate, or oblong-ovate, convex ; margins invo- 

 lute ; aperture longitudinal, narrow, extending the whole 

 length of the shell, dentate on both sides, and effuse at 

 the extremities ; spire very small, generally hidden in 

 the adult, or perfect shells. 



1. C. OVIFOBMIS. 



fig. 34, 35. 



The Egg-shaped Cypraea, pi. XXX. 



