Turbo. 



MOLLUSCA. 



253 



2. Fusus CLATHRATUS. — The Ladder Fusus, pi. XXXIII.* 

 fig. 42. 



F. clathratus. Sowerby, Geo. Tr. 2nd Ser. IV. p. 344, pi. 

 18, fig. 19. 



Somewhat pyriform ; spire short ; body large ; longitudinally 

 ribbed and striated ; four narrow, waved, transverse ribs divide 

 the surface of each volution into three portions resembling 

 cells ; aperture rather wide. 



The Greensand, Blackdown. ' 



3. Fusus EusTicus. — The Rustic Fusus, pi. XXXIII.* figs. 

 40, 41. 



F. rustie^is. Sowerby, Geo. Tr. 2nd Ser. IV. p. 344, pi. 18, 

 fig. 18. 



Short, rather ventricose ; spire short, with four or five rounded 

 volutions, which, as well as the body, are crossed by ten to 

 twelve prominent knobbed longitudinal ribs, giving a square- 

 ness to the sides ; whole surface transversely striated ; aperture 

 obliquely elongated, contracted both above and below ; pillar-lip 

 reflected. 



The Greensand, Blackdown. 



4. Fusus QUADRATUs. — The Squarish Fusus, pi. XXXIII.* 

 fig. 83. 



F. quadratus. Sowerby, Geo Tr. 2nd Ser. IV. p. 343, pi. 

 18, fig. 17. 



Fusiform ; body and spire forming reverse cones from the 

 centre of the body, which is square, with two obscure transverse 

 keels ; spire with four volutions, about a fourth of the length 

 of the shell ; base acute ; the whole covered with vride-set thin 

 stria; ; aperture sub-rhomboidal. 



The Greensand, Blackdown. 



5. Fusus RiGiDUs. — The Rigid Fusus, pi. XXXIII.* figs. 

 30, 37, 38. 



F. rigidus. Sowerby, Geo. Tr. 2nd Ser. p. 343, pi. 18. f. 16. 



Elongated, fusiform, with five or si.v volutions ; body length- 

 ened ; spire occupying about a third of the shell ; the whole 

 covered with longitudinal moderately prominent roughened ribs, 

 ventricose in the middle ; compressed above, and transversely 

 striated ; aperture elliptical, rather more than half the length 

 of the shell, and contracted both above and below; beak va- 

 riously elongated, with its edge sometimes a little reflected. 



The Greensand, Blackdown. 



6. Fusus liiBRicATUs. — The Imbricated Fusus, pi. XXXIII.* 

 figs. 70, 71. 



F. mhricatus. Brown, Wem. Mem. VIII. pi. 1, figs. .5, 6. 



Turreted, with si.\ volutions, flattened above ; spire abruptly 

 tapering to au acute apex ; the whole with broad, lamellar, un- 

 equally long thin ribs, broadest above, and slightly inflected at 

 the edges, terminating at tlie base of the body in front, and 

 running to the point of the back behind ; aperture semi-ovate, 

 rounded above and contracted below, slightly twisted to the 

 right ; pillar-lip broad, well defined, and replicate at its base ; 

 outer-lip thin and slightly reflected. 



The Pleistocene Marine Formation, Dalmuir, on the Clyde. 



1. Cancellabia minuta. — The Minute Cancellaria, pi. 

 XXXIII.* fig. 73. 



Turreted ; spire shorter than the body, with three volutions ; 

 aperture oblong, somewhat contracted ; surface with considerably 

 raised smooth longitudinal ribs, the interstices with transverse 

 striae. 



1 . Pleurotoma articulata. — The Ai'ticulated Pleurotoma, 

 pi. XXXVII.* fig. 20. 



P. articidata. Sowerby, Sil. Syst. p. 612, pi. 5, fig. 2. 



Turreted, with eight or ten very convex, deeply divided 

 volutions, with the sinus nearly in the middle, forming rather 

 a broad band; surface smooth, with a few sharp lines of 

 growth. 



The Upper Ludlow Rock, Ludlow, and near Ledbury. 



1. TuRRiTELLA GREGARiA. — The Gregarious Turritella, pi. 

 XXXlII.* figs. 81, 82. 



T. Gregaria. Sowerby, Sil. Syst. p. 603, pi. 3. fig. 1. 

 Subulate, \vith six convex smooth volutions ; aperture orbicu- 

 lar ; length from four to six lines, width two to three lines. 

 The Upper Ludlow Rock, Horeb Chapel. 



2. Turritella obsoleta.— The Obsolete Turritella, pi. 

 XXXIII.* fig. 88. 



T. obsoleta. Sowerby, Sil. Syst. p. 003, pi. 3, figs. Tn. 

 Subulate, smooth, with nine convex volutions ; aperture 

 round ; length one inch and a fourth, width five lines. 

 The Upper Ludlow Rock, Horeb Chapel, and Foliudre. 



3. Turritella cancellata.— The Cancellated Turritella. 

 pi. XXXIII.* fig. 75. 



T. cancellata. Sowerby, Sil. Syst. p. 042, pi. 20, fig. If*. 



Subulate ; longitudinally striated, with spiral unequal ribs 

 on each volution. 



The Lower Silurian Rocks, Maudiuara, I>landovcry, Hope 

 Mill Shelve. 



1. Turbo Pryce.e.— Price's Turbo, pi. XXXIII.* fig. 00 

 T. Priced. Sowerby, Sil. Syst. p. 042, pi. 21, fig. 19. 

 Body large, with an angular middle ; spire short ; umbilicus 



deep and curved. 



The Lower Silurian Rocks, Mandinam, Llandovery. 



2. Turbo corallii.— The Coral Turbo, pi. XXXIII.'^ f. 70. 

 T. corallii. Sowerby, Sill. Syst. p. 612, pi, 5, fig. 27. 



3 D 



