LAMELLIBEANCHIATA. 



31 



108. P. triphOOki, Zittel, Voy. Novara, Falce., p. 52, pi. x\.,f. 4. 

 Sub-orbicular, sub-equivalve, radiately ribbed ; right valve with twenty 

 to twenty-two rounded elevated ribs, of about equal width to the inter- 

 mediate grooves ; the ribs simple near tlie umbo, but slightly grooved 

 towards the tnargin ; grooves with a central raised line, which gets 

 obsolete towards the umbo, the whole crossed with concentric strise ; 

 left valve flatter, with twenty-three to twenty-five rounded ribs not so 

 elevated as on the right valve, broader than the intermediate grooves ; 

 ribs simple near the umbo but grooved towards the margin ; grooves 

 generally with a central raised line near the margin ; ears sub-equal, 

 radiately ribbed and transversely striated. Height, 4"8 ; length, 4"8. 

 Young sliells have no rib in the grooves. 



Localities. — Napier ; Maunga-pakeha Taipo, East Coast, "Welling- 

 ton ; Waitotara ; Castle Point, East Coast, Wellington ; Lyndon. 



109. P. accrementa, fip- nov. Sub-orbicular ; inequivalve ; with 

 from thirty to thirty-three radiating ribs ; ribs rounded, and on the 

 right valve elevated ; simple close to the umbo, but soon dividing 

 into several smaller ones ; interstices with a small central rib extend- 

 ing nearly to the umbo ; the whole finely concentrically striated ; 

 ears(?). Height, 3-8 ; length, 3-8. 



Localities. — Napier ; Awatere ; Motanau (l) ; Mount Caverhill. 



110. P. difl3.UXa, sp. nov. Sub-orbicular ; with twenty-five radi- 

 ating ribs ; ribs broad, flat, simple near the umbo, but grooved near the 

 margin, and occasionally divided into two ; covered with sharp scales ; 

 grooves round, narrower than the ribs, finely transversely striated, 

 without any central raised line ; ears sub-equal, radiately ribbed and 

 transversely striated. Height, 3 ; length, 3. 



Localities. — Weka Pass (m). 



111. P. hutdlinsoni, sp. nov. ; Hector, Cat. Col. Mus., p. 

 183, &c. Sub-orbicular, inequivalve ; right valve convex, with from 

 thirty-five to forty radiating ribs ornamented with pointed scales, 

 about equal to the interstices ; interstices with an elevated scaly line 

 down the centre ; left valve flattened near the umbo, with from seventy 

 to eighty fine scaly radiating lines ; ears sub-equal, large, radiately 

 ribbed, those o£ the left valve and the inner upper margin of the right 

 anterior ear transversely striated. Height, 4 5 ; length, 4 5. 



Localities. — Kaipuki ; Oamaru ; Weka Pass (m) ; Tata Island ; 

 Takaka. 



112. P. beethami, sp. nov. Sub-orbicular ; sub-equivalve ; 

 longer than high ; right valve convex, with about fifty low radiating 

 ribs, which in the middle are small and much narrower than the 

 grooves, but get broader towards each end, and have a steep slope on 

 the outer side, but on the inner gradually sloping ; towards the 

 margin they are crossed by undulating, imbricating, concentric stria^ ; 

 left valve flatter, with numerous small radiating stria^, crossed by con- 

 centric, imbricating, scaly lamina? ; ears sub-equal. Height, 4'6 ; 

 length, 5"5. 



Localities. — Upoko Ngaruru, East Coast, Wellington. 



