56 



MOLLUSCA. 



Triton. 



Rostellaria Buccinoides. Sowerby, Geo. Trans. IV. 2nd 

 series, p. 336, pi. 11, fig. 17. 



Shell subulate ; body short ; spire long, consisting of eight 

 rounded volutions, each furnished with a single varix, and ter- 

 minating in an acute apex; whole shell covered with numerous, 

 slightly bent, longitudinal ribs ; outer lip destitute of a lobe. 



Found in the Gualt. 



FAMILY V CANALIFERA. 



Shell with a canal of greater or less length, situated 

 at the base of the aperture ; the outer lip differing but 

 little in the young and adult state. 



Sub-division I. Having a permanent varix on the 

 outer lip; and varices on the spire. 



Genus XVIII.—TRITON.— iawiarcA. 



Shell oblong; spire rather prominent, and acute at the 

 apex ; volutions with never more than two on each ; 

 aperture nearly round; outer lip thickened; inner or 

 pillar lip generally rugose ; beak somewhat elongated, 

 and turned backwards ; operculum of a horny texture. 



1. T. CANALicuLATUM. — The Canaled Triton, pi. XXXIV. 

 fig. 7, 8. 



Succinwn canaliculatmn. Sowerby, Min. Conch. V. p. 14, 

 pi. 415, fig. 2, 2. Bticcinum desertuni, Brander, fig. 18, 19- 

 Nassa canaliculata, Fleming, Brit. An. p. 341. 



Shell elongated ; spire consisting of six volutions with some- 

 what flattened sides, and separated by a depressed canaliculate 

 suture, which is provided with a prominent margin ; upper 

 volutions with strong longitudinal ribs, which are less marked 

 in two or three of the lower volutions, but these are provided 

 at irregular intervals with a few varices ; whole shell trans- 

 versely striated; inner lip smooth and flattened; outer lip 

 thickened, with crenulations internafly, but plain at the margin; 

 aperture ovate, with a slight canal at its upper extremity ; beak 

 short and curved. 



Found plentifully in the London Clay at Barton Clilf and 

 Muddiford. 



Genus XIX MVREX.—Linnaus. 



Shell subturreted, more or less elongated ; spire for 

 the most part prominent, terminating in an acute apex, 

 furnished with three or more rows of digitated, muri- 

 cated, or spinous varices, or with an irregularly foUaceous 

 or lacerated fiinge ; aperture suborbicular ; columella 

 smooth; beak generally much elongated, sometimes very 

 long, and frequently recurved, provided with a horny 

 operculum. 



1. M. CORONATUS The Crowned Murex, pi. XXXIV. 



fig. 33, 34. 



Murex coronalus. Sowerby, Min. Conch. III. p. 52, pi. 

 230, fig. 3. 



Oblong-ovate, turreted ; spire consisting of four or five volu- 

 tions, which are slightly concave above, and terminating in a 

 somewhat obtuse apex ; body and spire covered with ten longi- 

 tudinal acute ribs, each of which terminate in a sharp point 

 above ; between the ribs the shell is widely striated ; aperture 

 oblong-ovate, wide, and flattened above, and narrowed beneath ; 

 inner lip broadly reflected on the columella ; outer lip thick, 

 and crenulated internally ; beak slightly curved. 



Found in the London Clay at Highgate Hill. 



2. M. MiNAX The Threatning Murex, pi. XXXIV. fig. 



9, 10. 



Murex minax. Brander, fig. 62. Sowerby, Min. Conch, 

 in. p. 51, pi. 229, fig. 2. 



Short; body large in proportion to the spire; spire consisting 

 of four narrow volutions, tuberculated above, and terminating 

 in a sharp apex ; body somewhat inflated, and provided with a 

 double zone of tubercles, those on the upper portion are spine- 

 shaped, and furrowed on their outer margins ; whole shell 

 covered with somewhat undulous and close, irregular strife ; base 

 of the body sulcated ; aperture nearly orbicular ; inner lip 

 smooth, and broadly reflected on the columella; outer lip thin; 

 beak short, and slightly curved. 



Found in the London Clay at Highgate Hill. 



3. M. TORosus.— The Knobby Murex, pi. XXXIV. fig. 20. 

 3Iurex tuberosus. Sowerby, Min. Conch, pi. 229, fig. 1. 

 Oblong-ovate, subterreted ; spire consisting of five or six 



volutions, ending in a pointed apex ; body and spire provided 

 with numerous, large, blunted, nearly obsolete ribs, which ter- 

 minate in large obtuse knobs on the most prominent part of the 

 volutions ; base convex ; the whole shell covered with many 

 rough lines of growth, which are crossed by thick-set, strong 

 spiral striae ; aperture ovate ; outer lip blunt ; beak short, and 

 slightly curved. 



Found in the London Clay at Highgate Hill. 



4. M. CRIST ATUS The Crested Murex, pi. XXXIV. fig. 1,2. 



Murex cristatus. Sowerby, Min. Conch. III. p. 52, pi. 230, 



fig. 1, 2. 



Ovate ; body large ; spire short, consisting of five abruptly 

 tapering volutions, terminating in a slightly pointed apex ; six 

 or seven longitudinal, sharp, prominent ribs cover the body of 

 the shell, and extend to the volutions of the spire, these are all 

 spiniform and canaliculated above, and each provided with three 

 plaits, formed by ribs behind ; whole shell covered with fine, 

 spiral striae ; aperture ovate, widest above ; beak curved, and of 

 medium length ; canal rather wide ; inner lip broadly reflected 

 on the columella above, and narrowing as it descends, with a 

 subumbilicus below ; outer lip considerably produced above, in 

 the form of a canaliculate elongation, and with two other pro- 

 duced undulations below ; back of the beak exhibiting two 

 tubular, projecting processes, being the former bases of the 

 beak, produced by the growth of the shell. 



Discovered in the London Clay at Highgate Hill, by G. B. 

 Snow, Esq. 



5. M. ARGUTUS The Sugar-loaf Murex, pi. XXXIV. fig. 



35, 36. 



Murex argutus. Brander, 13. Sowerby, Min. Conch. IV. 

 p. 59, pi. 344. 



