458 MAZATLAN UNIVALVES 
f. 11.—Schub. & Wagn. ia Chemn. Suppl. p. 150, pl. 233, 
f. 4096.—C. B. Ad. Pan. Shells,no. 68, p. 75. 
Monoceros cingulatus, Mike. in Zeit. f. Mal. 1850, p. 180, no. 46. 
Bueccinum cingulatum, Wood, Ind. Test. pl. 24, f. 167. 
Turbinella cingulata, Kien. Icon. Conch. p. 36, pl. 20, f.1.— 
Less. Rev. Zool. Jal. 1842.— Kust. Conch. Cab. p. 31, pl. 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 cestus. 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, Vermetide, &c. Labium 
thick, corrugated near the p‘aits, with an infrasutural lengthen- 
’ ed tooth, forminy a slight sutural canal. Spire rather elevated, 
or depressed. Shoulder somewhat rounded, or sharply keeled. 
The largest sp. measures long. 2°38, Ll. sp. °94, lat. 1°78, div. 80°. 
An elevated sp. 2 AEB Ea Sonte.  leedae eres 
A depressed sp. Us (oy, tar oda were Leosg@eee Toc. 
Hab.—W. Mexico, Humboldt & Bonpland, teste Lam. non 
Val.—Panama; in clefts of rocks at low water; Cuming.— 
Do. and Taboga, not uncommon; C. B. Adams.—Mazatlan ; 
extremely abundant; L’pool & Havre Coll. 
Tablet 2080 contains 3 sp. shoulder somewhat rounded, ele- 
vated.—2081, 4 do. normal, (one with operculum.)—2082, 3 do. 
depressed.—2.83, 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 PRINCEPS, Sow. 
Sow. Tank. Cat. App. p. 16.—Kien. Conch. Ic. p. 6, no. 4, 
pl. 12, 13.— Rve. Conch. Syst. vol. it. p. 184, pl. 231.—Lam. 
An. s. Vert. vol. ix. p. 436, no. 10.—Mke. in Zeit. f. Mal. 
1851, p. 17, no. 82. 
