3IONILKA. 



251 



The upper surface is ornamented with narrow, elevated, sharp lirse, 

 of which three are stronger, alternating with two or three smaller 

 ones ; about 12 similar ones are on the base; all of them are crossed 

 and made subgranose by closely crowded growth-lines. The umbili- 

 cus is moderate, surrounded by a peculiar callus, which shows only 

 growth-lines. The aperture is almost rhombic ; the coltimella oblique 

 below in the middle of the callous excavated. On a white ground 

 there are strewn red dots and larger spots. The apex is white or 

 ru>e-red. The umbilical callous is reddish-brown. Alt. 9i, diam. 

 12ji mill. Allied to T. crenulatus Mke., but differing in the colora- 

 tion, deep sutures and umbilical callous. (Philippi.) 



Inside the reef at Tongatabu, off Nukalofa, 18 fins. (Watson.) 



T. belcheri PHIL., Zeitschr. f. Mai. 1849, p. 148; Conchyl. Cab., 

 p. 302, t. 44, f. 3. WATSON, Challenger Kept., p. 71. 



M. RIG ATA Philippi. PL 41, figs. 32, 33. 



Shell eoiioidal, umbilicate, transversely closely sulcate, longitu- 

 dinally closely striate ; whitish ; clouded with brown ; whorls 

 rather convex, the last rounded ; base plano-convex, closely sul- 

 cate ; umbilicus funnel-shaped, dilated, modified by two spiral 

 callouses ; columella arcuate, base truncate. (P7w7.) 



The shell is somewhat flatly-conoidal, with 7 moderately convex 

 whorls. The penult, has about 8 elevated lines, often in pairs; 

 the last whorl has 12. They are decussated by dense oblique 

 elevated growth-lines, as are also the slightly wider interstices. 

 The base is level, and has about 8 narrow slightly elevated con- 

 centric lira?. The umbilicus is pretty narrow, but at the last 

 whorl is widely funnel-shaped, showing two* rounded spiral ribs, 

 the lower terminating in the denticle at base of the columella. 

 The aperture is rounded rhombic ; the throat sulcate within ; the 

 columella produced outward Avith a somewhat reflexed margin. 

 The color above is whitish or pale rust-yellow, with brown spots ; 

 beneath it is lighter with wavy interrupted brown lines, and darker 

 umbilical border. Alt. 10, diam. 15 mill. This species stands 

 midway between T. solandri and T. calliferus. It is separated from 

 the first by the broader umbilicus, the slightly elevated spiral lira?, 

 which on the base are narrow and crowded; from the last the 

 much less developed umbilical callus separates it. (Philippi.) 



Adelaide, Australia. 



T. rigatus PHIL. Zeitschr. f. Mai. 1848, p. 124; Conchyl. Cab., p. 

 184, t. 28, f. 14. 



