82 LAMKLLIBRANC1IIATA. 



margin crcnulate. Variable in colour, usually brown marbled with 

 purplish and more or less marked with white. Height, T35 ; breadth, 

 1-15. 



* 118. P. pic88, Reeve. Shell orbicular, compressed, equilateral, 

 nearly equivalve, valves rayed with twenty-one narrow ribs, interstices 

 excavated ; white variegated with gre} r and brown-black ; ears large, 

 nearly equal. (Reeve.} 



* 119. P. dieffbnbacllii, Reeve. Shell sub-triangular, pe- 

 culiarly impressly plicated on both sides near the umboncs, equilateral, 

 nearly equivalve, valves often irregular, profusely radiately lineated 

 and ridged, the lines and ridges everywhere narrowly squamate ; red- 

 dish brown or violet ; cars very unequal. (Reeve) 



Apparently the same as P. zealandicc. 



* 120. P. nmltiCOStatllS, Reeve. Shell ovate, rather thin, gib- 

 bous, equilateral, equivalve ; valves rayed by thirty rather distant, 

 narrow, obscurely nodulcd ribs, finely scaled at the sides ; deep ver- 

 milion, unspotted, marbled with white at the umboncs ; ears very 

 unequal. (Reeve.) 



Apparently the same as P. zealandicB. 



121. P. radiatUS, sp. nov. Orbicular, equivalve, compressed, 

 with about eighty equal rough radiating stria? ; ears unequal ; thin ; 

 margin creuulated. Bed, ochraceous, or brownish purple. Height, 

 1-8; breadth, 17. 



Stewart's Island, 13 fathoms. 



122. P. (Dentipecteil) vellicatus, sp. nov. Irregularly 

 orbicular, sub-cquivalve, produced in front, longitudinally irregularly 

 five-plaited, and with small radiating ribs, crossed by fine concentric 

 stria? ; ears unequal ; hinge line obscurely striated ; margin undu- 

 lating. Eeddish, purplish, or white spotted with pink. Height, 1'6 ; 

 breadth, TG. 



Common. 



VOLA. 



Sub-orbicular ; inequivalve ; superior valve flattened ; rayed ; ears 

 nearly equal. 



123. V. latiCOStatUS, Gray, Die/. N.Z., \\.,p. 2GO; Peden novae 

 Zealand ice, Reeve. Thick, with fourteen to eighteen smooth radiating 

 ribs, the larger ones sometimes depressed, with one or two interrupted 

 longitudinal grooves ; flat valve with the ribs distant and narrower. 

 Reddish brown to purplish white ; interior white or brownish. Height, 

 55; length, 6. 



Common.. Chatham Islands. 



LIMA. 



Equivalve, compressed, obliquely oval ; anterior side straight, 

 gaping ; posterior rounded, usually close ; umbones apart, eared ; 

 hinge area triangular, cartilage pit central ; adductor impression lateral, 

 large, double; pedal scars two, small. 



Widely spread. 



