220 



quisit-elv sculptured with flat conc-entric ribs, varying greatly 

 in width, some twice, some four times as wide as the irter- 

 spaces ; others are only cords, not so wide as the intervals. 

 They are higher on their convex than their concave edge. 

 Numerous radial lirae, increasing by intercalation, scallop the 

 ribs more markedly along their concave than their convex 

 margin, forming circular depressions in the interspaces. At 

 the anterior and posterior areas of the shell these scallops 

 become triangular rather than circular, and so form lozenges 

 in the interspaces. Where the radials cross the ribs, if these 

 are very narrow, they produce a tubercle with a central radial 

 furrow ; if wide, they cross as a lira, with a central furrow, and 

 sometimes another radial furrow is found on either side of 

 this. 



Di7n elision. ^. — Umbo-ventral, 8 mm. ; antero-posterior, 

 7'5 mm. ; section of closed valves, 3 '25 mm. : largest example, 

 10*5 mm. by 10'3 mm. 



Locality. — Type, off Cape Jaffa, from 90 fathoms, with 1 

 other valve ; 35 miles south-west of Neptune Islands, from 104 

 fathoms, 62 valves. 



Limopsis erectus, Hedley and Petterd. 



Llinopsis erectus, Hedley & Petterd, Records Aiistr. Mus., 

 vol. vi., part 3, p. 224, pi. xxxviii., figs. 14, 15. Type locality, 

 250 fathoms, off Sydney. 



Dredged 35 miles south-west of Neptune Islands, 104 

 fathoms, 6 valves : off Beachport, 150 fathoms, 1 valve, 200 

 fathoms, 1 valve; ofi' Cape Jaffa, 130 fathoms, 17 valves, and 

 300 fathoms, many small and mostly poor valves, but some 

 with epidermis. The epidermis is abundant, of flaxen, bristly 

 setce, long towards the ventral border. 



Nuculina (Cyrilla, A. Adams, s.g.) concentrica, n. sp. • 



PI. xxvii., tigs. 4, 4rt, 4h. 



iVlinute, obliquely-oval, equivalvular, inequilateral, 

 higher than long, moderately solid, white, smooth, with six 

 concentric equidistant imbricating steps. Umbos prominent, 

 prosogyre, incurved, approximate. The front side at the 

 upper third is oblique and nearly straight, being faintly in- 

 curved ; then rather suddenly roundly angulated, beyond 

 which it is uniformly openly curved. The posterior side 

 has a uniform gentle arcuation, and the basal outline is dis- 

 tinctly more sharply curved. The hinge-plate is broad. The 

 teeth of the left valve lie in front of those in the right valve, 

 and the left lateral tooth lies outside the right. There are 

 six cardinal teeth in each valve, all behind a pit lyine- be- 

 neath and slightly in front of the umbo. The three nearest 



