244 



The operculum represented by fig. 228 is of a sub-cylindrical spiral 

 form, and exhibits no sutures on its outer surface, the striae being continu- 

 ous all across. There is no muscular process. 



Figure 230 has no suture, and although more nearly related to fig. 228 

 than it is to the other, is still quite distinct therefrom. 



There Avas also another operculum found at Pistolet Bay, which is nearly 

 straight, and two inches long by six lines in width. 



These four opercula, differing so widely from each other, prove that 

 there are also as many distinct species of 3Iavlurea to which they belong. 

 Accordingly at Cape Norman we find fragments of what appear to be 

 forms different from those above described. I propose to name them as 

 follows : 



Maclurea Sylpha. (N. sp.) 



Description.— This species is founded on a silicified fragment consisting 

 of the middle three whorls of a specimen which appears to have been 

 somewhat larger and more nearly globular than any of those above noticed. 

 Spire flat ; width across the three whorls, 12 lines ; last whorl 4 lines 

 wide ; height of the aperture as nearly as can be ascertained 10 lines ; 

 width of the umbilicus, 7 lines. The umbilicus, which is quite empty in 

 the specimen, is cylindro-conical ; the edge scarcely at all projecting, and 

 the sides of the Avhorls flat. It extends quite to the apex. 



Maclurea Psyche. (N. sp.) 



Description. — A specimen 18 lines wide, has the aperture 10^ lines in 

 height ; umbilicus 6 lines wide. The spire is flat, but the number of Avhorls 

 cannot be made out. The edge of the umbilicus is narrowly rounded as it 

 is in M, oceana ; inner side of the Avhorl gently convex. In general 

 aspect resembles a sub-globular form of M. oceana., differing therefrom in 

 having a narrower umbilicus which does not ascend to the apex, and in 

 having the aperture more extended in the vertical direction. 



