IMS ORTHALICU8. 



visible to the naked eye ; lip well expanded or 

 n-tlexed, white or light colored. 



Group of O.fraseri, p. 192. 



d l . Spiral stria- tine and close, the shell rather 

 Mimoth; lip and entire aperture pure white, 

 the Conner expanded or reflexed ; colnmelkl 

 with a strong fold abo\ e. 



Group of 0. deburghia, p. 196. 

 e 1 . No spiral striation ; peristome colored. 



Group of 0. labeo, p. 199. 



Subgenus OUTIIALICUS (restricted). 



The .-election of //. sultoiui Dilhv. (guU i IKI-KH li'UKi auet.), as typi- 

 cal of 0,-llmlints \>y Gray and Troschel, restricts that group to a few 

 large, richly variegated shells inhabiting the (iuianas, western Peru 

 and central and northern liolivia all abundantly watered forest 

 regions. The exact definition of the species and varieties awaits 

 fuller knowledge of their geographic distribution, which in large part 

 still remains to be mapped. 

 O. SULTANA (Dillwyn). PI. 47, tigs. ',, 7, 8. 



Shell large, ovate, with rather short, conic spire and ventricose 

 la-i \\horl; thin; immature specimens more or less fragile. Last 

 whorl burl', closely veined with irregular and anastomosing, or !<- 

 tooncd purplish or brown stripes, and encircled by three principal 

 blackish-purple or brownish-purple spiral bands irregularly inter- 

 rupted by white or creamy spots or stripes ; narrower or indistinct 

 bands in the interval.- between the main ones (a variety with live 

 band.-) ; the upper band usually formed of a broad series of large 

 dark alternating with light (or white) blotches; the spire cloudy 

 marked with festooned stripes and t\\o or three spot-girdles or bands 

 of angulation. Surface lustreh-.-s. linely plicatulate obliquely, decus- 

 sated l.v close spiral stria-, at narrow intervals stronger. \\ horls C>, 

 moderately convex, the first '2\ forming the densely thimble-punctate 

 ol.lu>e nepioiiic shell, the earlie.-l i \\ o whorls dark brown above ; last 

 whorl verv large; suture not dcllt-xed anteriorly. 



Aperture lar-e, oblique, ovate, bluish white (lilac colored in a 

 \ariei\ ) and vari(.u>ly mottled \\ilhin; jieri-lome thin, nnexpanded, 

 light bro\\n (or in a variety, black-brown in adults, with a rather 

 \\ideinternal border of the.-ame color, fading through purple into 



