"96 MONODONTA. 



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

 '(1828). (Not T. atratus Gniel.) 



The name of atratus Wood has priority iu Monodonta, ])ut lias 

 Tiot been adopted by authors. 



Tliis 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. 



jVI. puxctulata Lamarck. PI. 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 Avith 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 jninctulata LiAM., An. s. Fer^., vii, p. 37. — T. jnmct- 

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

 p. 176, t. 58, f 2. — Osilin AoAMSon, Voy. au Senegal, p. 178. — 

 Monodonta o§ilin 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 Avhite, and 

 the rounded, not bicarinate body-whorl. 



Subgenus Diloma Philippi. 



Section Diloma Phil, (restricted). 



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

 Conchyl., 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 



