84 



RECORDS OF THE ATJSTBALIAN MUSEtTM. 



DESCRIPTION OF a NEW BIVALVE, LIMA ALATA, from 

 SANTA CRUZ. 



By 0. Hedley, Conchologist. 



Shell large, thick and 

 strong, colour uncertain, 

 in outline but slightly 

 oblique, subelliptical, 

 sharply truncate above 

 and roundly produced 

 below, in transverse sec- 

 tion moderately rounded, 

 in breadth two-thirds the 

 length. Hinge line long, 

 a third of the length of the 

 valve, nearly straight, set 

 at about an angle of thirty- 

 five degrees to the median 

 line of the valve. The 

 narrow and shallow liga- 

 meutal area is oveihung 

 by the small, sharp, pro- 

 duced umbo. The anterior 

 auricle is enormously de- 

 veloped, thickened, reflec- 

 ted, and sharply and 

 strongly recurved ; the 

 posterior is straight and 

 moderately developed. The 

 exterior is everywhere 

 regularly furrowed by 

 numerous small grooves 

 equal to their interstices. 

 These are about a hundred in number, are deepest and broadest 

 on the auricles and above, finest on the centre of the valve. 

 They diverge at a small angle on each side of a median line ; trans- 

 versely concentric growth lines indent and distort them. 



Length, 70 mm. ; breadth 50 mm. 



Locality. — Santa Cruz, S. Pacific. 



Type. — Au.stralian Museum. 



The material for the preceding description is a single, rather 

 worn and discolored right valve, collected by Mr. J. Jennings on 



