ARCHEGOCOPTIS. 303 



ing, convex plug. Purple-brown, the upper whorls and latter 

 part of the last dull red, the whole more or less covered with 

 a whitish or light brown coat of very fine, short striae, which 

 give the shell a dingy or dusty appearance; specimens de- 

 nuded of this being dark purple or red ; suture usually marked 

 with a white line. Surface lustreless, minutely and densely 

 sculptured with very fine, wavy, interrupted striae; a row of 

 pits above the suture and some irregular spots elsewhere free 

 of striae. Whorls 8 to 9%, nearly flat, the last shortly built 

 forward, and having the base encircled by a narrow, very 

 strongly projecting keel, below which the striae are obsolete. 

 Aperture subcircular, oblique, the peristome pale and but 

 slightly expanded. Axis slender and straight. 



Length 31, diam. 8 mm. ; whorte 8. 



Length 32, diam. 7.4 mm. ; whorls 9%. 



Haiti: Aux Cayes (C. Ross) ; Jeremie (Rolle). 



Cyl. eximia PFR., Malak. BL, iv, 1857, p. 232; Monogr., iv, 

 p. 694 ; vi, 363 ; Novit. Conch., iii, p. 439, pi. 97, f . 30-32 ; Mai. 

 Blatt., xxiii, 1876, p. 215; 1869, p. 91. CROSSE, J. de C., 

 1868, p. 347; 1891, p. 137, pi. 1, f. 5, 6. SOWERBY, Conch. 

 Icon., xx, pi. 1, f. 6 (gay). Helix (Cochlodina) petiveriana 

 FER., Tabl. Syst., p. 61, no. 498 (1822 ?), based upon poor and 

 not certainly identifiable figures. 



The peculiar sculpture is characteristic. It is related to 

 A. crenata, but differs in the far stronger basal keel, the 

 smaller aperture and less expanded peristome, and the clear- 

 cut sculpture. The specimens before me are from Aux Cayes ; 

 I have seen only crenata from Jeremie. 



The apex is scalar, turned down at the tip, and coarsely 

 sculptured with wide-spaced riblets (pi. 41, fig. 69). 



2. A. CRENATA (Weinland & Martens). PL 41, figs. 73, 74, 



75 ; pi. 38, figs. 5, 6, 7. 



Shell cylindric below, the upper half or more slowly taper- 

 ing to a wide truncation closed by a flat, subvertical pustulate 

 plug. Penult, and next earlier whorls usually dull purplish- 

 blue in part, the rest of the shell dull red or white. Surface 

 having a worn or dusty appearance, very finely and closely 

 sculptured with waved striae, generally showing also some low, 

 coarse spiral girdles or malleation, and above the suture a 



