HELIX-RHAGADA. 191 



There is also a variety of this shell with numerous grayish bands ; 

 or perhaps the brown bands change to gray when the shell is dead. 



Group of H. silveri. (Glyptorhagada). 



Shell more or less strongly keeled at the circumference ; surface 

 corrugated by strong oblique folds ; outer lip simple, not reflexed. 



H. SILVERI Angas. Vol. IV, pi. 36, fig. 44. 



Shell perforated, globose-conic, thin, corrugated by strong, oblique, 

 flexuous folds, cretaceous ; spire conoid, apex obtuse, suture distinct ; 

 whorls 6, a little convex, the last descending in front; periphery 

 slightly carinated, base convex. Aperture oblique, suboval, margins 

 converging, joined by a thin callus, the outer margin thin, acute, a 

 little expanded, columellar margin expanded above, reflexed, half 

 covering the perforation. (Angas.) 



Alt. 16, greater diam. 22, lesser 18 mill. 



The Eastern Plains, S. Australia. 



H. silveri ANGAS, P. Z. S. 1868, p. 257, wood-cuts. 



H. KOORINGENSIS Angas. Vol. IV, pi. 36, figs. 45, 46. 



Shell umbilicated, somewhat globosely lenticular, rather thin, 

 strongly obliquely flexuously corrugated, the corrugations more or 

 less elevated and irregular, the interstices crossed with short, im- 

 pressed, interrupted, transverse lines, especially on the basal portion 

 of the last whorl, cretaceous,, white ; spire flatly conoidal, apex ob- 

 tuse, sutures impressed ; whorls 5, slightly convex, the last very 

 strongly flatly carinated, not descending in front, the base tumid 

 around the umbilicus ; aperture oblique, subquadrate ; outer lip sim- 

 ple ; columella arcuate, slightly thickened and partly expanded 

 over the umbilicus. (Angas.) 



Diam. maj. 1 inch, min. 10, alt. 6 lines. 



30 miles northeast of the Burra Mines, South Australia. 



This remarkable species is very similar in the character of its 

 sculpture to H. silveri, Ang. ; but the corrugations are less regular, 

 the umbilicus is larger, the shell is flattened, and the last whorl very 

 prominently keeled. (Angas.) 



A. Kooringensis ANGAS, P. Z. S. 1877, p. 33, woodcuts. Cox, 

 Proc. Linn. Soc. N. S. Wales for 1877, 2d. ser. iv, p. 1062, t. 20, f. 

 3, 4, 5, (Animal) March, 1888. 



