176 CHLOROSTOMA. 



beaded upon the upper surface, the interstices between them mi- 

 nutely spirally striated ; on the penultimate whorl they number 

 about 6 ; below the periphery the line are finer, closer, and nearly 

 smooth ; last whorl obtusely angulate or rounded at the periphery ; 

 base rather flattened, somewhat concave around the umbilicus, and 

 generally eroded in front of the aperture ; aperture oblique ; outer 

 lip beveled to an acute edge, which is usually margined with green 

 and is sulcated or crenulated, the furrows corresponding to the lirse 

 of the outer surface ; the pearly throat is also more or less sulcate ; 

 columella arcuate, expanded above in a bright green callus which 

 partly surrounds the umbilicus, at its base green, bearing a tuber- 

 cular tooth, followed by several smaller ones ; basal margin smooth 

 or denticulate within ; umbilicus wide and deep, white or greenish 

 within. Alt. 22, diam. 25 mill. 



Rio Janeiro, Northward to West Indies. 



Trochm viridulus GMEL., Syst. Nat., xiii, p. 3574. PHILIPPI, 

 Conchyl. Cab., p. 75, t, 14, f. 5. FISCHER, Coq. Viv., p. 210, t. 70, f. 

 1 (not T. viridulus Mke.) T. Cruciatus "Chemnitz," PHILIPPI, 

 Conchyl. Cab., p. 76, 1. 14, f. 8 (not of Linn.) T. articvlatus D'ORB., 

 Voy. dans. VAmcr. Mcrid., p. 409. 

 Under the above specific name I am compelled to unite a number 



of species hertofore considered distinct. The description and figures 



given above apply to the typical form found on the E. Coast of S. 



America. This form is nearly always green beneath the superficial 



coat. 



Var. RETICULATUM Wood. PL 29, figs. 63, 64, 68, 69. 



This form is more depressed than C. viridulum and smaller ; the 

 base is flatter ; the periphery carinate ; the lirse of the upper surface 

 more regular, more distinctly beaded, the interliral interstices with 

 fewer spiral striae, often with minute beaded lirulse. Coloration as 

 in C. viridulum, consisting of radiating stripes. Aperture and 

 columella tinged with green or white. Alt. 15, diam. 18-19 mill. 



Panama to Mazatlan. 



T. retieulatas WOOD., Lid. Test. SuppL, t. 6, f. 38. FISCHER, Coq. 

 Viv., p. 212, t. 70. f. 2. T. brazilianus MENKE, Syn. meth. Moll., p. 

 142 (1830). Philippi, Conchyl. Cab., p. 76, t. 14, f. 10. 



A form precisely like this in every character except that it has a 

 somewhat more rounded periphery is before me from the Gulf 

 coast of Costa Rica. 



