210 



Ohs — Angas, in Proc. Zool. Soc, 1867, p. 221, made his 

 name a synonym of Patella costata ( Lottia costata), Sowerby, 

 Moll., Beechey's Voy., t. 39, f. 2, 1839; and as Acmo&a cos- 

 tata, Sow., his shell is referred to by Ten. -Woods, Proc. Roy. 

 Soc. Tasm., 1877, p. 50, and op. cit., 1878, pp. 44 and 45; 

 Pilsbry, in Tryon's Man. Conch., vol. xiii., p. 51, pi. xxxvi., 

 f. 72-77 ; Adcock, Handlist of Aquatic Moll., S. Aust., 1893, 

 p. 9, No. 394; Tate and May, Proc. Linn. Soc, N.S. Wales, 

 1901, vol. xxvi., part 3, p. 411 : Pritchard and GatUff, Proc. 

 Roy. Soc, Vict., 1903, vol. xv. (n.s.), part 2, p. 194. But 

 Hedley affirms them to be different species, loc. cit. 



It may reach the size of 2 in. long, 1'7 broad, and '8 

 high. It is nearly always narrower anteriorly, sometimes 

 markedly so ; very rarely it is quite elliptical. The height 

 may be 7 in. in a shell only I'l in. long, or only '5 in 1*6, just 

 twice as high proportionally. The shape may be acutely 

 conical and straight-sided or flat-topped and convex-sided. 

 The ribs vary from 14 to 27, increasing by intercalation with 

 age. The interstices may be prettily ornamented with close- 

 set fuscous crescentic lines, convex towards the apex ; these 

 may climb the sides of the ribs, or cross them ; they are more 

 marked in beach-worn shells. The interior may be wholly 

 white, including the margin ; even the spatula may be scarcely 

 tinted or distinguishable. The latter may be blackish-brown, 

 or of any lighter tint of brown, its anterior and posterior 

 parts being usually much darker. The margin may have no 

 colouration, or very dark spots may mark all or some of the 

 interspaces between the ribs. In addition to these a light- 

 brown band may completely margin the inner border, or this 

 may be found alone of any darker tint up to a purplish 

 black. More or less rusty colouration mav be found between 

 the spatula and the margin, generally in blotches. 



Acmsea marmorata, Ten.-Woods. 



Proc. Roy. Soc, Tasm., 1876 for 1875, pp. 156, 157, and 

 1877 for 1876, p. 53; Pilsbry., Tryon, Man. Conch., 1891, vol. 

 xiii., p. 52, pi. xlii., figs. 66-70; Adcock, Handlist Aquatic Moll., 

 S. Anst., 1893, p. 9, No. 399; Tate and Mav, Proc. Linn. Soc, 

 N.S.W., 1901, vol. xxvi., pt. 3, p. 412; Pritchard and Gatliff, 

 Proc. Roy. Soc, Vict., 1903, vol. xv. (n. s.), pt. 2, p. 197. 



Fatella. lafi&trigata, Angas, Proc. Zool. Soc, Lond., 1865, p. 

 154, and p. 186, No. 196a; Adcock, loc. cit., 1893; Pritchard and 

 Gatliff, loc. cit.; TIelciovisciis lati.<itrigat(t, Anqas. Pilsbry., loc. 

 cit., p. 143. 



Locality. — From Port MacDonnell to Port Victoria, 

 Spencer Gulf. 



Obs. — My largest individual from Port MacDonnell 

 measures 24 mm. long, 22'5 wide, and 10 high. The alti- 



