RHYT1DA. 123 



R. PREVOSTIANA, Crosse. PI. 28, figs. 41, 42. 



Umbilicus perforate, partly covered, thin, with subdistant 

 lamelliform striae ; yellowish brown 1 , more or less maculated with 

 light chestnut, particularly at the suture ; whorls 5, with im- 

 pressed suture, base subplauate and regularly costulate. 



Diam. 6, alt. 4*5 mill. 



New Caledonia. 



The color varies, sometimes uniform horny-white, or dark 

 corneous, or horny-white more or less maculated with orange- 

 brown. 



*** 



R. PTYCHOMPHALA, Pfeiffer. PL 22, figs. 16-18 ; PI. 28, fig. 39. 



Rather thin, glossy, closely, irregularly, frequently anasto- 

 mosely striated, without spiral sculpture ; olive-brown, with 

 some more or less distinct chestnut strigations, and a faint 

 yellow band around the umbilicus ; whorls 4j, the last inflated 

 and deflected at the mouth, somewhat flattened. 



Diam. 1*4, alt. '5 inch. 



Port Essington, Australia. 



Figs. 17, 18. from Kiister, represent a shell not fulty grown, 

 and without the yellow umbilical band ; Pfeifler's original de- 

 scription is based on a similar shell. I add (fig. 16) a fully 

 developed shell from Cox's work, and a smaller one (fig. 39) 

 from Reeve. 



R. LEICHARDTI, Cox. PI. 22, fig. 23. 



Widely umbilicated, somewhat solid, closely obliquely costu- 

 late above, scarcely shining, opaque; olivaceous red ; whorls 4^, 

 the last descending at the aperture. Diam. 1/4, alt. '65 inches. 



Australia. 

 R. STRANGEI, Pfr. PI. 22, fig. 27 ; PI. 28, fig. 49. 



Umbilicated, rather thin, shining, pellucid, closely striate 

 above, decussated by very numerous impressed spiral lines ; 

 yellowish, reddish or horny chestnut, sometimes with light 

 chestnut strigations ; whorls 5, not descending in front ; base 

 nearly smooth, glossy. Diam. 1, alt. *4 inch. 



New South Wales. 

 R. LINCOLNIENSIS, Pfr. PI. 22, fig. 28. 



Umbilicated, thin, strongly closely striate and slightly granu- 



