138 



ridged at the base, medially with conspicuous transverse sigmoid 

 strii^ ; somewhat abruptly attenuated below the middle line. 



Aperture ovate, outer lip thin ; columella with two inconspicu- 

 ous anterior plaits, and a large posterior one. 



Dimensions. — Length, 40; breadth, 13 ; length of aperture, 20. 



Localities. — Lower beds at Muddy Creek ; and in well sinking, 

 Murray Desert; Table Cape! 



The figured example of which the dimensions are given is from 

 the Murray Desert ; in size it very much exceeds the type speci- 

 men from Muddy Creek, which is an immature shell, and whilst 

 the representation of it gives the riglit proportions, yet it does not 

 show the slight flattening at the suture ; intermediate examples 

 occur at the latter locality. 



4. Mitra uniplica, spec. nov. Plate iv., fig. I2. 



Differs from the foregoing by its more convex whorls more 

 shouldered at the suture, wider body-whorl, which is less at- 

 tenuated anteriorly, and by its single columella plait. 



Dimensions of specimen, wanting posterior part of spire, of five 

 whorls ; length, 49 ; width, 17 ; leng-th of aperture, 26. 



Locality. — Blue clays at Schnapper Point. 



5. Mitra varicosa, spec. nov. Plate v., fig. i. 



Shell stout, fusiformly conic, of seven whorls, ending in a small 

 papillary pullus. Ordinary whorls slightly convex, a little 

 ventricose behind anterior suture, and inconspicuously dej^ressed 

 in the posterior-third ; transversely closely wrinkled and striate, 

 crossed by fine distant equal lira?, about 12 on the penultimate 

 whorl. 



Last Avhorl varicosely dilated at the commencement and at 

 about the middle ; columella with four strong plaits, and two on 

 the posterior part of the aperture. 



Dimensions. — Length, 24; widtb, 10; leng-th of aperture, 13. 



Locality. — Clayey-green-sands, Adelaide bore. 



6. Mitra atypha, spec. nov. Plate iv , fig. 6. 



Shell stout, narrow-ovate, blunt at each end; whorls six,, 

 smooth, slightly convex. Aperture oval, outer lip lirate within, 

 columella with four approximate plaits. 



Dimensions. — Length, 10; breadth, 4*5; length of aperture, 5.5. 



Locality. — Upper beds at Muddy Creek. 



7. Mitra complanata, spec. nov. Plate v., fig. 12. 

 Shell rather thin, elongate-ovate, with a blunt apex, and rather 

 attenuated at the front ; whorls six, smooth, shining, slightly 

 convex. Aperture narrow-elliptical ; outer lip sharp, smooth with- 

 in ; columella with four distant plaits. 



