458 MAZATLAN FNIVALVES 



f. ll.Sckub. fy Wagn. in CJiemn. Suppl. p. 150, pi. 233, 



f. 4096. (7. B. Ad. Pan. Shells t no. 68, p. 75. 

 Monoceros cingulatus, Mice, in Zeit.f. Mai. 1850, p. 180, no. 46. 

 Buccimnn cingulatum, Wood, Ind. Test, pi, 24, f. 167. 

 Turbinella cingulata, Kien. Icon. Conch, p. 36, pi. 20, f. 1. 



Less. Rev. Zool. Jul. 1842. Kust. Conch. Cab. p. 31, pi. 7, f. 8. 



This remarkable shell is distinguished at once from Mono- 

 ceros by its plaited columella as in Lathirus, and its very strong, 

 twisted, unguiform operculum which can scarcely be distin- 

 guished from that of Turbinella csestus. The labrum has a 

 broad shallow posterior sinus, and two deep narrow ones on 

 each side of the stoutly projecting horn (sometimes '65 long). 

 It is internally faintly lirate, much advanced in the middle 

 (to the level of the horn), serrated at the edge, where it is 

 tessellated by the extremities of the darker bands. The shell, 

 substantially white with broad and fine dark bands, is covered 

 with a smooth, adherent, brown epidermis ; and is almost 

 always encrusted with coralline, Vermetidse, &c. Labiuin 

 thick, corrugated near the plaits, with an infrasutural lengthen- 

 ed tooth, forming a slight sutural canal. Spire rather .elevated, 

 or depressed. Shoulder somewhat rounded, or sharply keeled. 

 The largest sp. measures long. 2*38, 1. sp. '94, lat. 1*78, div. 80. 

 An elevated sp. 1'8, '88, T24, 70. 



A depressed sp. ,, 1*72, '54, 1*3, 90. 



Hob. W. Mexico, Humboldt fy JBonpland, teste Lam. non 



Vol. Panama ; in clefts of rocks at low water ; Cuming. 



Do. and Taboga, not uncommon ; C. B. Adams. Mazatlan ; 



extremely abundant ; L'pool fy Havre Coll. 



Tablet 2080 contains 3 sp. shoulder somewhat rounded, ele- 

 vated. 2081, 4 do. normal, (one with operculum.) 2082, 3 do. 

 depressed. 2083, 3 sp. shoulder sharply angulated, elevated. 

 2084, 3 do. normal. 2085, 3 do. depressed. 2086, 2 sp. lip 

 mended after fracture. 2087, 2 sp. horn in process of renewal. 



GENUS FASCIOLARIA, Lam. < 



584. FASCIOLARIA PEINCEPS, Sow. 



Sow. Tank. Cat. App. p. 16. Kien. Conch. Ic. p. 6, no. 4, 

 pi. 12, 13. Eve. Conch. Syst. vol. ii. p. 184, pi. 231. Lam. 

 An. s. Vert. vol. ix. p. 436, no. 10. Mice, in Zeit. /. Hal. 

 1851, p. 17, no. 82. 



