320 



Pecten accrementa, Hutton. 



1873. Pecten accrementa, Hutton, Cat. Tert. Moll. N.Z. p. 31. 



Distinguished by its broad, fiat, rounded, radiating costag, ■which 

 are from twenty-three to twenty-five in number ; these are simple 

 near the umbo, but divide into several small ones with growth ; 

 a smaller rib, extending nearly to the umbo, is placed in each 

 space between the larger costae ; it is inequivalve ; the expansions 

 are well developed. 



Dimensions. — Height 62 mm. ; length 55 mm. 



Form, and Loc. — Miocene: "Duncan's," East Coast, Is'orth 

 Island, New Zealand. 



L. 10501. Imperfect example, in which the larger costse are 

 medially sulcated. Sir James Hector Coll. 



L. 10502. Several impressions of the interior of both valves 

 in friable, shelly, argillaceous sandstone, probably referable to 

 this species. Sir James Hector Coll. 



L. 10543. Shell relatively broader than in typical examples ; 

 whilst the costae are smaller and more numerous. It appears 

 to be a local variation. Sir James Hector Coll. 



Pecten triphooki, Zittel. 



1865. Fecten triphooki, Zittel, Eeise der Novara, Palaontologie, Bd. i. 



Abth. ii. p. 52, taf. xi. fig. 4. 

 1873. Pecten triphooki, Hutton, Cat. Tert. Moll. N.Z. p. 31. 

 1893. Pecten triphooki, Hutton, Linn. Soc. N.S.W., Macleay Mem. Yol. 



p. 88. 



Closely allied to P. accrementa, but the valves are slightly more 

 convex and relatively broader, the radiating costas are more distant 

 from each other, and much raised ; the costae are sulcated and 

 striated, and the interstices between them have each an elevated 

 median lineation. 



Di)nensions. — Height 118 mm.; length 122 mm. 



Form, and Loc. — Miocene : Napier, New Zealand. 



1. 10530. Example of the adult, both valves, [ Old Collection.^ 



