212 TURBO. 



An extremely variable species. Frequently several tuberculate 

 line encircle the base; and in this strongly nodose variety the in- 

 cremental stria) are usually inconspicuous. In another form the 

 spiral line are not noticably tuberculate. 



T. SHANDI Hutton, 1873. Unfyured. 



"Shell with three smooth spiral ribs near the periphery, .with two 

 or three nodulous ribs both above and below; white, spotted with 

 reddish or purplish brown. 1 ' 



Chatham Is. 



The above description, (copied from Proc. Linn. Soc. X. S. Wales 

 ix, p. 355) is all the information I can give regarding this species. 

 The copy of Button's "Catalogue of Marine Mollusea of New 

 Zealand" to which I have access is without the signature containing 

 his description. The operculum is unknown. Hutton places it with 

 doubt in Callopoma, probably not its correct position. 



Subgenus NIXELLA Gray, 1850. 



Shell depressed, widely umbilicate ; whorls lirate, sometimes car- 

 mate. Operculum oval, nucleus excentric ; outside concave in the 

 middle, with two strong spiral ribs, the outer margin thin, granulate. 



A ustralo-Zealandic Pro rince. 



T. STAMIXEUS Martyn, 1784. PI. 42, fig. 38 ; pi. 49, fig. 46. 



Shell large, orbiculate, conic, solid, umbilicate, whitish, mottled 

 and strigate with dark brown ; whorls 6, with dense lamellose in- 

 cremental striae and coarse spiral lirre, the upper ones carinated, the 

 carina becoming obsolete on body-whorl ; sutures canaliculate, bor- 

 dered below r by a row of nodules ; aperture round, oblique, white 

 within ; columella white, perforated by the wide and deep umbili- 

 cus, and with a spiral groove extending to the base. 



Alt. 60-80, diam. 75-110, mill. 



S. Australia; New Ireland; New Zealand. 



Operculum (pi. 59, figs. 15, 16) oval, flat within, with four whorls, 

 nucleus situated one-third the distance across the face ; outside white^ 

 excavated at the center, with two strong spiral ribs, the inner one 

 decidedly the stronger ; a sharply granular tract outside the outer 

 rib. The figure given does not well show the character of the ribs. 



Synonyms: T. torquatus Gmel., "T. stramineus Wood" of authors. 



This species varies much in degree of elevation and carination. 

 It merges by insensible degrees into the var. lamellosns. In the 

 typical form the sutures are frequently simple, not canaliculate, and 

 the subsutural tubercles are wanting. 



