136 Transactions. 



Difiers from C. armoricus by the spiral tlireadlets on the spire, the rim- 

 like ridge which overhangs the sutures, and the accompanying concavity 

 of the whorls. The material consists of a single example. C. armoricus is 

 recorded from Komiti Point,* Kaipara Harbour, and it is interesting to 

 find a form so nearly akin in the Hampden beds. 



Melina zealandica Suter. (Plate X, fig. 20; Plate IX, fig. 21.) 

 For all references see N.Z. Geol. Surv. Pal. Bull. No. 5. 



A description derived from very fragmentary materials is given in the 

 above-mentioned publication, pages 68, 69. Pla*te viii, fig. 4, is a part of 

 the hinge ; plate xiii, fig. 1, is the large fragment from Shrimpton's, and 

 not Ostrea mackayi, and fig. 2 is the latter species. 



The species is not uncommon in the Nukumaru and Waipipi beds ; 

 numerous large fragments, including an almost complete hinge of a right 

 valve, were obtained. Another example of hinge partly embedded in rock 

 has both valves locked in natural position. Attached to a mass of rock 

 a complete valve was noted, which was much eroded, but presented an 

 approximate indication of the general outline. From this, aided by large 

 fragments, we derive the figure of the restored shell. 



The shell is apparently subquadrate, somewhat swollen, the umbo near 

 to the anterior end, the anterior ear small with the margin immediately 

 below prominently inflexed. The ventral margin and posterior end may 

 to some extent have been completely eroded, as the lamellar structure 

 would lend itself to this, but it does not appear to have been prominently 

 winged. The hinge is massive and wide, with four or five conspicuous 

 resilifers. The length of the hinge exceeds 140 mm., and several measure- 

 ments indicate that the united valves are not less than 90 mm. in diameter. 



Amphidesma (Taria) crassiformis n. sp. (Plate X, figs. 22, 23.) 



Shell of medium size, massive, triangular ; beaks almost at the posterior 

 end which is abruptly truncated, strongly and acutely angled ; the anterior 

 dorsal margin long, downward sloping and almost straight, the anterior end 

 narrow and rounded, ventral margin slightly curved ; the posterior trunca- 

 tion is slightly concave as it approaches the lip-margin, and on the end 

 there are two, usually three, feebly-raised curved ridges. The median area 

 of the valves and towards the ventral margin sometimes has a slightly 

 concave appearance. Sculpture is irregular shallow concentric corruga- 

 tions with fine striae, the latter on the posterior end pronounced. Hinge 

 conspicuously massive ; right valve with deeply excavate sockets above 

 the laterals, the posterior much the shorter ; in the left valve the anterior 

 lateral elongated and with a double tubercle on its crest, the right short 

 high and triangular ; cardinals in both lamellar and oblique. Adductor- 

 scars, pallial line, and sinus deeply impressed, the sinus short and with a 

 broadly rounded apex. Lip-margins smooth. 



Length, 80 mm. ; height, 60 mm. 



Locality, Nukumaru, in blue sandy clay. 



Type to be presented to the Wanganui Museum. 



Material consists of three valves, a right and left of which are almost 

 perfect. Readily distinguished by its massiveness and the abrupt heavy 

 truncation. 



* C. armoricus occurs at Pakaurangi Point, not Komiti Point, which is some two 

 miles distant. 



