1392 I II UR I NCR IX A 



Monocondylcea franciscana Cr.ESSiN, Conch. Cab. Ano., 1876, 



p. 251, pi. Lxxiv, figs. 4, 5. — Simpson, Syn., 1900, p. 912. 

 Aplodon franciscana von Ihering, Arch, fiir Nat., 1893, p. 



115- 



The shell is not very solid, and is more nearly orbicular than 

 that of any other species. 



Monoconi)yi,.t;a i^kntiformis Lea. 



Shell irreglarly obovate, short, convex, solid, inequilateral ; 

 beaks rather high but not very full, turned forward over a 

 small lunule ; dorsal line behind the beaks arched ; posterior 

 slope almost squarely truncated ; anterior end much narrowed ; 

 base rounded, considerably fuller behind the middle; epider- 

 mis dirty green ; there are one or two faint rays on the pos- 

 terior ridge ; nacre lurid purplish, iridescent behind, thicker 

 in front ; prismatic border wide. 

 Length 40, height 33, diam. 17 mm. 

 Southern Brazil. 

 Monocondyl(ca lentiformis Lea, Pr. Ac. N. Sci. Phila., X, 

 1866, p. 34 ; Jl. Ac. N. Sci. Phila.. VL 1868, p. 272, pi. xxxvi, 

 fig. 86; Obs., XII, 1869. p. 32, pi. xxxvi, fig. 86. — Clessin, 

 Conch. Cab. Ano.. 1876. p. 250. pi. lxxix, figs. 4, 5. — Simp- 

 son, Syn., 1900, p. 912. 

 Margaron (Monocondyla^a) lentiformis Lea, Syn., 1870, j). J2. 

 Aplodon lentiformis von Ihering, Arch, fiir Nat., 1893, p. 67. 

 The epidermis is badly worn ofif over most of the surface of 

 the disks in the type, and the cavity of the shell is blotched 

 with greenish-blue. It is a more solid, less inflated species 

 than franciscana, is longer and more obovate. 



The following species is unknown to me : 

 Monocondylcea tamsana Dunker, Mai. Bl., V, 1858, p. 226. 



Genus IHERINGELLA Pilsbry, 1893. 



Plagiodon I,ea, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 79. 

 Iheringella Pilsbry, Nautilus, VII. 1893, p. 30. 



Shell solid, inflated, rounded to rhomboid in outline, with a 

 more or less developed posterior ridge ; beaks high, curved 



