CHLOROSTOMA. 



keel ; the base is concentrically, rather deeply furrowed, the 6 

 furrows narrower than the intervening ridges. In the umbilicus, 

 which perforates almost to the apex, all of the whorls are visible, 

 encircled by an acute carina ; the aperture is subquadrate, nacreous, 

 smooth within, and has a groove indicating the place of the exter- 

 nal keel; the columlla is S-shaped, and ends in a blunt tooth, 

 before which there is a small acute denticle ; above, the columellar 

 plate is callous, and covers a small portion of the umbilicus. The 

 pretty markings of the shell consist of oblique, regular wide black 

 streaks, separated by spaces as broad as themselves, on a white 

 ground. 



Alt. 24, diam. 25 mill. There are also narrower forms. (Philippi.') 



Coast of Peru. 



T. Dielaleucos JONAS, Zeitschr. f. Mai. 1844, p. 169. PHILIPPI 

 Abbild. u. Beschreib., ii, Troekus, t. 6, f. 7 ; and Conchyl. Cab., p. 

 185, t. 28, f. 16. 



Evidently closely allied to Chlorostoma rubroflammulatwn. 

 C. FUSCESCEXS Philippi. PI. 61, figs. 42, 43. 



Shell depressed-conical, narrowly umbilicate, acute, brown ; 

 whorls densely spirally striated ; nearly flat, subangulate at the 

 sutures ; last whorl subangular at the periphery ; columella sub- 

 excised, base bidentate, above produced in a short lobe partly im- 

 pinging upon the umbilicus. (Phil.) 



The shell consists of 5 to 6 whorls, and has a great likeness to the 

 Mediterranean T. (Gibbula) varias in size, form of the whorls, stria- 

 tion and coloration ; the whorls are almost entirely flat, only con- 

 vex above near the suture ; the last whorl is pretty angular, almost 

 marginated ; the aperture is rounded-quadrangular, the columella 

 strongly excavated, with two denticles below, separated by a nacreous 

 depression, above produced into a callous which lies partly around 

 the umbilicus, but is not so conspicuous as in other species. The 

 umbilicus is narrow, white, distinctly bounded by a blackish band, 

 which goes to the lower tooth of the columella, on others the color 

 is brown, marbled with a few lighter flecks. There seems to be a 

 variety in w T hich there are separated elevated, carina-like lints. 



Alt. 11, diam. 14 mill. (Philippi.') 



Chili. 



T. fuscescens PHIL., Abbild., etc., i, Trochus, t. 3, f. 8. (1884.) 

 (Not Otnphalius fascescens Carpenter et and., Chlorostoma liyula- 

 tur/i Mke.) 



