MONODONTA. 95 



short, obtusely subdentate near the base, spreading at the insertion 

 into a heavy callous, which covers the umbilicus. 

 Alt. 25, diani. 23 ; alt 30, diam. 27 mill. 



Western Europe ; Portugal; Mogador ; British Is. 



Troehus crassus Pult., Cat. Dorset., p. 44. — Montagu, Test. Brit, 

 i, p. 281 (1803).— Philippi, Conchyl Cab., p. 164, t. 26, f. 15, 16.— 

 Forbes and Hanley, Hist. Brit. Moll, t. 65, f. 4, 5. — Fischek, Coq. 

 Viv., p. 202, t. 67, f. 2.—Lineatus Da Costa, Brit. Conch., p. 100, 

 t. 6, f. 7. — T. lineatus Jeffreys, Brit. Conch., iii, p. 317 ; v, t. 62, f. 

 6.— Hidalgo, 3hl. Mar. de Esp., t. 61, f. 1, t. 62, f. 1-5.— B., D. et 

 D., Moll, du Roussillon, t. 49, f. 8, 9. — Monodonta lugubris Lamarck^ 

 An. s. Vert., vii, p. 37. 



I have not seen the Catalogue of Pulteney, which is quoted by 

 Montagu for this species. The name lineatus of Da Costa, used by 

 many authors, should be considered inadmissible on account of the 

 failure of that author to use generic in combination with his sj)ecific 

 names. 



This species is similar to M. turbinata in form, but usually has the 

 outlines of the spire more convex. The culumella projection or 

 tooth is nearer the base than in the turbinata, and the diverse color- 

 patterns will serve to further distinguish the two species. 



M. TAMsi Dunker. PL 20, figs. 3, 4 ; pi. figs. 



Shell imperforate, conic, solid, spire conical, apical whorls eroded, 

 the following dull cinereous or purplish-black, marked with several 

 spiral rows of white spots, or with longitudinal zigzag white stripes, 

 the base generally tessellated or striped with white ; whorls 5 to 6, 

 the upper ones marked with spiral impressed lines in young speci- 

 mens, and two carinre, the latter giving the last whorl a squarish 

 form ; aperture oblique, the lip not much thickened within ; col- 

 umella short, obsoletely subdentate at base, above at the insertion 

 with a heavy white callous spread upon the base, invading the um- 

 bilicus, and wholly closing it, or leaving only a narrow pit. 



Alt. 17-19, diam. 16 mill. ; alt. 23, diam. 19 mill. 



Cape Verde and Canary Is.; Coast of Guinea; Cape of Good 

 Hope. 



Troehus tavisii Dunker, in Phlippi, Ahhild., i. p. 189, Troehus, 

 t. 5, f. 3 (1845).— Philippi, Conchyl. Cab., p. 160, t. 26, f. 5.— 

 Dunker, Ind. Moll. Gain., p. 16, t. 2, f. 40-42.— Fischer, Coq. 



