Lima.} PELECYPOUA. 885 



Sect. 2. MANTELLUM. H. and A. Adams, 1858. 

 Mantellum (Bolten), Ad. G.R.M., ii, 558. Type : L. Mans, Grael. 



Shell thin, ventricose, oblique ; anterior side of shell widely gaping ; 

 submargins not impressed. Hinge - margin oblique ; cartilage - pit 

 central, projecting into the cavity of the shell. 



3. Lima angulata, Sowerby. 1843. Plate 63, fig. 4. 



Lima angulata, Sowerby, P.Z.S., 1843, 23 ; Thes. Conch., i, 1843, 86, pi. 22, 

 f. 39, 40 ; Chall. Rep., xiii, 289 ; Tate, P.R.S. S.Aust., ix, 109 ; Medley, 

 Mem. A.M., iv, 310 ; Button, J. de Conch., xxvi, 55 ; M.N.Z.M., 172 ; 

 P.L.S. N.S.W., ix, 531 ; Conch. Icon., viii, pi. 3, f. 13 ; Catliff, P.R.S. 

 Vic., xx (n.s.), 37 ; Verco, T.R.S. S.Aust., xxxi, 314. L. basilanica, 

 Adams and Reeve, Voy. " Samarang," 75, pi. 21, f. >. L. orientalis, 

 Ad. & Rve., op. cit., 75, pi. 21, f. 7. 



Shell small, thin, transparent, oblique, ventricose, white, finely 

 radially costate. Beaks distant, sharply pointed, incurved. Ears 

 small, the anterior somewhat larger, triangular. Anterior end obliquely 

 descending, straight ; posterior end prominently convex at the middle ; 

 basal margin regularly rounded. Cardinal area narrow. Sculpture 

 consisting of fine inequidistant radiate riblets, the interstices usually 

 slightly broader than the costse, crossed by fine and dense concentric 

 growth-lines. Colour white. Interior polished, showing the radiate 

 sculpture. Margins finely dentated, but smooth anteriorly. Hinge- 

 line rather short, the greater part of it occupied by the broadly tri- 

 angular cartilage. Adductor-scar indistinct. 



Diameter Ant. -post., 11 mm. ; dorse-ventral, 14 mm. : thickness. 

 7 mm. 



Type in the British Museum. 



Hob. Off Lyttelton, in 100 fathoms ; south-east of Cape Saunders. 

 in 100 fathoms ; twenty-four miles south-east of Long Point, in 120 

 fathoms (E. R. Waite) ; Snares, in 50 fathoms (Captain Bollons) ; 

 ten miles north of Enderby Island, in 85 fathoms (E. R. Waite). Also 

 Australia, Philippine Islands, New Caledonia, Panama, Acapulco. 

 Mexico. Juan Fernandez Island. The type is from Panama and Bay 

 of Caracas. 



Fossil in the Pliocene. 



Subgen. 2. LIMATULA, Searles Wood, 1839. 



Limatula, S. Wood, A.M.N.H., iii, 1839, 2(30. Type : L. subauriculata,. 

 Montagu. 



Valves closed, equilateral, more or less distinctly mesially sulcate ; 

 sculpture radial. 



KEY TO SPECIES. 



A. Valves with a well-defined median sulcus . . . . . . Suterl. 



B. Valves without a median sulcus, regularly radiately ribbed . . bullata. 



