195 



Taken in King George Sound on the beach, and in 10 to 15 

 fathoms very many, and in 28 fathoms a few; on Bunbury 

 beach, 3 ; in Geographe Bay, 15 fathoms, 2 ; off Fremantle, 

 in 6 fathoms, 1 . They vary greatly in width ; some may 

 be 6'75 mm. long by 2'25 mm. wide, and others 5'25 mm. 

 long by 175 mm. wide, and so confirm the suggestion made 

 in 1906 that N. compressa, Verco, is only a variant. They 

 are none of them quite so wide as the South Australian 

 examples, 5*6 mm. by 2*8 mm. ; and none of them quite so 

 narrow, 5 mm. by 1*6 mm., but are intermediate. At King 

 George Sound they are much more common in the shallow 

 dredging than anywhere in South Australia. 



Nacella crebrestriata, Verco. 



Nacella crebrestriata, Verco, Trans. Roy. Soc. S.A., 1904, vol. 

 xxviii., p. 144, pi. xxvi., figs. 20, 21; 1906, vol. xxx., p. 208; 

 1907. vol. xxxi., p. 101; and 1912, vol. xxxvi., p. 183. 



King George Sound beach, 3; Yallingup, 5; Rott- 

 nest Island. 2. 



Var. roseoradiata, car. nov. 



This is typically a broader and more elliptical shell, has 

 about two-thirds as many radial striae, and 15 or 16 deep-pink 

 axial rays, gradually increasing in width. 



This was taken at Guichen Bay, South Australia; but 

 in much better condition and more abundantly at Ellensbrook 

 and Yallingup. Some examples are oval rather than ellip- 

 tical, being narrower anteriorly ; they vary somewhat in 

 width, and one has its lateral margins incurved, as though 

 the narrow surface — e.g., Zostera — on which it lived had 

 shrunk, and consequently had led to the contraction of the 

 sides of the aperture of the shell. 



Type is in my cabinet. 



Nacella stowae, Verco. 



Nacella stowce, Verco, Trans. Roy. Soc, S.A., 1906, vol. xxx., 

 pi. x., figs. 4, 5; 1912, vol. xxxvi., p. 183. 



King George Sound beach, 8 ; Bunbury beach, 4 ; Rott- 

 nest Island, 2. Identical with the South Australian speci- 

 mens, but in poor condition. 



Acmaea patellavecta, n. sp. PI. xv., figs 5-7 ; 



pi. xvi., fig. 5. 



Shell solid, elliptical, conical. Apex at the junction of 



the anterior and middle third, eroded. Margin in profile 



concave at the sides (due to its habit of living on a patella). 



Anterior slope nearly straight, posterior somewhat convex. 



