324. MOLLUSC A. TROCHUSID.E. Tkochus; 



EXTINCT SPECIES. 



1. T. agglulinans. — Depressed, conical, smooth ; base expanded, with a 

 broad waved margin ; whorls externally deformed ; pillar-cavity plicate ; 

 aperture oblong. — (T. umbilicaris, Brander, Foss. Hant. f. 4-5.) — Sower. Min. 

 Conch, t. xcviii. — Smaller figure. — London Clay. 



2. T. BenetticB — Depressed, conical ; upper surface obliquely wrinkled ; 

 base expanded, with a broad waved margin ; whorls externally irregular ; 

 pillar-cavity plicate, partly covered ; aperture narrow. — Soiver. Min. Conch. 

 t. xcviii Larger figure. — London Clay. 



3. T. anglicus. — Conical, base rather convex ; volutions squarish, with tu- 

 bercles upon their angles, transversely carino-striate, and a rounding eleva- 

 tion in their centres ; lines of growth decussating the three central striae ; 

 pillar imperforate — List. Conch, t. mdcccxxxvI. f. 16. Soioer. Min. Conch, t. 

 cxlii. — Lias. 



4. T. IcBvigatus. — Conical, nearly smooth ; sides straight ; base convex, with 

 an obtuse margin ; aperture rhomboidal, v/ith rounded angles ; no pillar cavi- 

 ty'. — Sower. Mm. Conch, t. clxxxi. f. 1 — Crag. 



5. T. similes. — Conical, sides straight, ornamented with many ti'ansverse 

 ridges, two or three of v/hich upon each whorl are gi-anulated ; base flattish, 

 concentrically striated ; aperture quadrangular ; pillar direct — Sower. JNIin. 

 Conch, t. clxxxi. f. 2 — Crag. 



6. T. angulatv^. — Conical, sides of the whorls concave ; base flattish ; mar- 

 gin carinated ; aperture acutely rhomboidal ; no pillar cavity — Sower. Min. 

 Conch, t. clxxxi. f. 3 — Inferior Oolite. 



7. T. dupUcahis Conical, sides of the whorls concave ; a double deeply 



crenulated carina round the base ; pillar cavity open, with a tubercular mar- 

 gin ; aperture quadrangular — Soiver. Min. Conch, t. clxxxi. f. 5 Under Oolite. 



8. T. dimidiatus. — Conical, base convex, with a carinated margin ; upper 

 part of the whorl concave, with an entire carina in the middle ; aperture pent- 

 angular; pillar direct and solid. — Sower. Min. Conch, t. clxxxi. f. 4. — Under 

 Oolite. 



9. T. punctatus — Conical, with straight sides, transversely striated ; upper 

 striae upon each whorl crossed by oblique undulations ; lower ones minutely 



ranulated ; a narrow band between the two sets Sower. Min. Conch, t. cxciii. 

 1. — Inferior Oolite^ 



10. T. elongatus — Conical, elongated, transversely striated ; striae near the 

 apex granulated ; each whorl slightly undulated near the upper edge, with an 



obscure band before the middle ; the inferior margin prominent Sower. Min. 



Conch, t. cxciii. f. 234. — Inferior Oolite^ 



11. T. abhreviatus Conical shortened, transversely striated ; striae obscure- 

 ly decussated by oblique lines of growth; inferior margin of each whorl very 

 prominent, obtuse, with an obscure band above it — Sower. Min. Conch, t. 

 cxciii. f. 5 Inferior Oolite. 



12. T.fasciatus Conical, umbilicate, decussate striated; whorls slightly 



convex, with a band around their middle ; base flattish ; aperture quadi'angu- 

 lar Sower. Min. Conch, t. ccxx. f. 1 — Inferior Oolite. 



13. T. arenosus Conical, very short, gi'anulated, whorls rather convex 



above, with a band along the middle ; base convex, in part nearly smooth. 

 — Sower. Min. Conch, t. ccxx. f. 2 — Inferior Oolite. 



14. T./jrominens.— Conical, short, whorls convex, finely striated, with a 



