MONODONTA. 



Viv., p. 177, t. 59, f. l. T. atratus WOOD, Ind. Test, suppl, f. 25 

 (1828). (Not T. atratus Gmel.) 



The name of atratus Wood has priority in Monodonta, but has 

 not been adopted by authors. 



This species is quite variable in coloration, the white appearing 

 either in oblique zigzags or in spots. The bicarinate whorls will 

 separate it from the preceding species. The young are perforate. 



M. PUNCTULATA Lamarck. PL 20, figs. 8, 9. 



Shell imperforate, conical, solid, deep purplish-brown or blackish, 

 dotted with white, the dots sometimes forming spiral series, and al- 

 ways elongated in the direction of the spiral ; surface nearly smooth, 

 sometimes showing traces of spiral grooves, which are always visible 

 on the young ; spire conoid, apex generally eroded and orange- 

 colored; whorls 6, convex, the last somewhat flattened or subconcave 

 around the upper part, the base convex, eroded and white in front of 

 the aperture ; aperture half-circular, the outer lip not much thick- 

 ened, edged with black, beautifully iridescent within, with ame- 

 thystine tints ; columella short, obtusely subdentate at the base, ex- 

 panding above into a callous, which covers axis and umbilicus, or 

 leaves a slight excavation or groove. Alt. 17, diam. 18 mill. 



Coasts of Senegal, W. Africa. 



Monodonta punctulata LAM., An. s. Vert., vii, p. 37. T. pum-t- 

 ulatus PHILIPPI, Conchyl. Cab., p. 165, t. 26, f. 17. Fischer, Coq. Viv., 

 p. 176, t. 58, f. 2. Otsilin ADAMSOU, Voy. au Senegal, p. 178. 

 Monodonta osilin DESHAYES in LAM. An. s. Vert. ed. 2, p. 182 (excl. 

 syn.) 



A species resembling some forms of the preceding in the somber 

 coloration, but differing in the more iridescent interior (in which 

 red is more conspicuous than green), the smaller dots of white, and 

 the rounded, not bicarinate body- whorl. 



Subgenus DILOMA Philippi. 



Section DILOMA Phil, (restricted). 



Diloma PHIL., Abbild. etc., i, p. 168 (1845) ; Handbuch der 

 onchyl., u. Mai., p. 209. H. and A. AD., Gen. Rec. Moll, i, p. 419. 

 FISCHER, Manuel, p. 820. TRYON, Struct, and Syst. Conch., ii, 

 p. 315. 



Diloma has been restricted by Fischer to the South American 

 species. The only diagnostic character separating these from the 



