Oliver. — Mollusca of the Kermadec Islands. 553 



Spondylus raoulensis n. sp. Fig. 49. 



Description oj Type Specimen. — Right valve attached to rock, irregular, 

 very deep at apex. Hinge-line straight, sides expanding at first gradually 

 then suddenly, forming a nearly circular outline. Planes of hinge area 

 and margin at right angles, contour of margin viewed laterally convex. 

 Hinge area triangular, slightly concave, sides sinuous. Hinge-teeth pro- 

 jecting, with a deep cartilage-pit between them. Sculpture : Hinge area 

 smooth, surface in contact with rock rough and irregular, otherwise with 

 indistinct radiating ribs and concentric growth-lines. Colour pink ; purplish 

 on the angles of the hinge area ; apex and hinge area mostly white. 



Diameter — Dorso- ventral, 63 mm. ; ant. -post., 54 mm. Hinge area — 

 Br.se, 30 mm. : height, 27 mm. 



Left valve (of another specimen) irregular, shallow. Cartilage - pit 

 narrow, triangular, formed by two raised ridges on hinge-plate converg- 

 ing at apex. Hinge-teeth high, rounded, their dorsal face overhanging a 

 marginal groove. Sculpture : There are 12 prominent but irregular radiat- 

 ing ridges, of which 6 high ones alternate with (3 lower ones. The inter- 

 spaces with close, wavy, lamellated. radiating ribs, slightly irregular in 

 size. Colour pink, darker on the ridges and ears. 



Diameter — Dorso-ventral, 73 mm. ; ant. -post., 72 mm. 



Variations from Type. — Large shells are massive and heavy. The angle 

 of the planes of hinge area and margin increase with age. The colour varies, 

 some shells being entirely purplish, others with much yellowish diffused 

 with pink, but the ears and angles of the hinge area are usually purplish. 

 Large right valve : Diameter — dorso-ventral, 125 mm. ; ant. -post., 98 mm. 

 Angle of planes of hinge area and margins, 135°. The hinge area varies 

 in, outline, and the apex points either forward or backward. Young 

 specimens have spines on the ridges ; these are probably worn off the 

 types, which are beach specimens. 



Habitat. — Single valves, often of large size, commonly washed up on the 

 beaches, Sunday Island. A fragment of pumicestone with a small live shell 

 attached was dredged in 25 m. off Sunday Island by R. S. Bell. 



Fossil. — Common in hard sandv tuffs of submarine origin, Devrell Islet. 

 (S. ostreoides Oliver, Trans. N.Z. Inst,, 43, 527.) 



Spondylus ostreoides E. A. Smith. 



Spondylus ostreoides E. A. Smith, " Challenger " Rep., xiii, pt. 35, 



326, 1885. 

 Recorded, E. A. Smith, I.e. 



Habitat. — Two single valves dredged in 950 m. south of Sunday Island 

 (" : Challenger " Expedition). 



Cyclopecten kermadecensis (E. A. Smith). 



Pecten kermadecensis E. A. Smith, " Challenger " Rep., xiii, pt. 35, 



302, 1885. 

 Recorded, E. A. Smith, I.e. 



Habitat. — Two valves dredged in 1,100 m. north of Sunday Island on 

 hard ground (" Challenger " Expedition). 



Pecten medius Lamarck. 



Pecten medius Lamarck, Anim. s. Vert,, vi, 163, 1819. 



Habitat.— Dredged alive in 30 m. off Meyer Island (W. S. Bell). 

 Distribution. — New Zealand, Tasmania, Australia, 



