438 Prof. F. M'Coy on two new Fossil Cowries. 



beds, with which latter it agrees better in its usually naked 

 sulcus; but the ends of the ridges are never dilated, and, in 

 addition to the same differences of the more arched mouth and 

 less inflected outer lip of the Australian species, the shell in it 

 is larger, thinner, and the ridges more elevated, thinner, and 

 further apart. 



Very common in the blue Tertiary clays and limestone be- 

 tween Mount Eliza and Mount Martha in the Bay. Very rare, 

 but of large size, in the blue clays of Muddy Creek near Grange 

 Cwm, five miles from Hamilton. 



CyprcBa gigas (M'Coy). 



Sp. CJi. Shell very large, thick ; form ovate, back very gib- 

 bous, somewhat spheroidally irregularly rounded ; base flattened 

 oval, much thickened, extending slightly in thick obtusely 

 rounded margins on each side of the anterior and posterior ends 

 of the shell (not in the middle) ; inner lip rounded, smooth 

 within, flattened near the anterior channel, slightly concave 

 before joining the tumid outer margin ; outer lip inflected, 

 tumid, broad, and the edge smooth in the middle, with nine or 

 ten nearly obsolete obtuse teeth near the anterior end, and a 

 few still fainter near the posterior end. Aperture narrow, mo- 

 derately curved, widest towards the anterior end, terminating in 

 deep narrow channels at each end, the anterior one reflected at 

 an angle of about 70° from the base, projecting upwards, form- 

 ing a reentering angle of 65° with the back, the posterior chan- 

 nel reflexed at upwards of 140°, obliquely subtx'uncate, inclining 

 forward, and adherent to the spire. Spire exposed, of two 

 whorls; apex obtuse, large; surface smooth. Length of large 

 specimens 8 inches, proportional width -r^, height -^^, height 

 of anterior channel tVo> of posterior one -j^, diameter of spiral 

 suture at base of spire -r^-o, width of middle of mouth -tb-o- 



This gigantic species far exceeds any known cowry in size, 

 and, like the large Eocene Tertiary C. tuberosa, is so completely 

 destitute of teeth on the inner lip as almbsli to belong to Ovula. 

 With the very oblique light of a candle, or by a delicate sense 

 of touch, faint indications of teeth may be detected, but scarcely 

 more than, under similar circumstances, may be found in the 

 recent Ovula ovum. The flattened base and thickened inner lip 

 forming an obtuse lateral projection at each end of the shell, 

 as well as the strong reflection of the channels, induce me to 

 place the present fossil in Cyprcea. 



In blue clay of Muddy Creek, ten miles south of Hamilton, 

 and in similar beds between Mount Eliza and Mount Martha 

 on the shores of Hobson's Bay. 



