122 



The aperture is rather more than one-third the length of the 

 ■whole shell ; it is elongately ovate, outer border arcuate, smooth 

 within, acute at the suture posteriorly, broad and truncated 

 anteriorly. The margin of the aperture is oblique with reference 

 to the axis of the shell. 



This species has hitherto been confounded apparently with 

 its congener M. alokiza, Tenison- Woods, fi*om which it differs, 

 however, in many important particulars. The protoconch of 

 M. muUisiilcata, as will have been noticed, is more fully developed ; 

 its spiral sulcations are much closer together from the earliest 

 stage ; the body- whorl is minus a subangulation, the margin of 

 the aperture is not parallel with the axis of the shell, and it 

 is wider and more arcuate ; finally, it is relatively more truncate 

 anteriorly. 



Dimensions. — Length 24'5 mm.; breadth 8mm.; length of 

 aperture 10 mm. 



Form, and Loe. — Eocene : Muddy Creek, Victoria. 



G. 9361. A series illustrating stages of growth, from the brephic 

 onwards. Furchased. 



Mitra uniplicata, Tate. 



1889. Mitra {Ettmitra) uniplicata, Tate, Trans. Eoy. Soc. South Aust. vol. xi. 

 pp. 135, 138, pi. iv. fig. 12. 



This is distinguished from M. alohiza and M. multisulcata in that 

 its nine whorls are much more convex, and the columella has only 

 one, prominent plication, with the suspicion of a second. The] 

 surface of the shell is covered by almost imperceptible spiral striae, 

 which, however, become much more pronounced and developed 

 into prominent spiral ridges on the anterior half of the body- 

 whorl. The sutures are deeply cut in, and peculiar indentations, 

 where spots of colour appear to have been, border the whorls in 

 that region. 



Professor Tate does not mention Muddy Creek as a locality for 

 this species, but the specimen in the Museum undoubtedly came 

 from there, and not from Schnapper Point. It is much larger, has 

 more whorls than the figured type, and is more perfect, though the 

 protoconch is wanting. 



Fimensions. — Length 69 mm.; breadth 18 mm.; length of 

 aperture 32 mm. 



